Welcome to Sports Mole for live coverage of the 113th US Open at Merion Golf Club in Pennsylvania.
The tournament returns to Merion for the first time in 32 years, but ground staff have been working overtime to get the course ready after being battered by torrential rain all week.
A forecast storm forced the players off after just seven holes of the opening round, but play resumed at 5.10pm (UK time), so stick around for the first-round action below.
Good afternoon! Welcome to Sports Mole for live coverage of the 113th US Open at Merion Golf Club in Pennsylvania. It's raining, it's pouring... so much so that the skies look apocalyptic. There's no play at the moment and the fans have run for cover as lightening cracks overhead. It's unfortunate for the ground staff, who pulled off something of a miracle to get the course playable for today.
Some of the players did manage to get on course before the warning buzzer rang out across the condensed course. The lead is currently enjoyed by Ian Poulter (-3), who started great guns by picking up shots on his first three holes.
Nicolas Colsaerts is two-under-par through seven holes. South African duo Tim Clark and Charl Schwartzel are both two-under through four, while Charley Hoffman is on the same score through two holes.
At the other end of the leaderboard we find Roger Tambellini (+6 through 6), Cliff Kresge (+4 through 6) and, surprisingly, Bill Haas (+3 through 4).
Sky Sports Golf on Twitter: "Very very heavy rain here now."
Storms were forecast for today, but you can never completely hang your hat on them. Well, in this case you can. The scenes at Merion look rather dull. I wonder if we will get any of the first rounds completed today? We could be in for a long one tomorrow or, God forbid, a Monday finish.
The good news is that the outlook for the weekend is dry, if a little cloudy. With Merion primed to play hard and fast, that could render this short course defenseless as it dries. Softer grounds could provide target practice, but it's never that simple. The USGA are famed for the challenging way in which they set out their courses for the US Open.
Pictures on Sky Sports News show standing water on some of the greens. That's not good news, it's already looking increasingly unlikely that we won't be completing the first round today. Whether we get any play at all is the question now. It looks like a pretty big storm on the weather maps.
The 11th hole, where many of the players will begin their rounds, is a big concern for ground staff. It's prone to flooding and will require some degree of care before play is resumed.
Let's take advantage of this break in play talk about some of the story lines heading into the tournament. Of course, the weather has grabbed the headlines all week, but one of the biggest talking points was the first meeting between Sergio Garcia and Tiger Woods after the Spaniard's "fried chicken" slur. The players, who have never really been best friends, shook hands on the practice range this week, but I don't think that buries the hatchet. Not for one second.
The comments were made at a European Tour awards dinner, not long after Garcia accused Woods of intentionally disrupting him during his swing at the Players Championship at Ponte Vedra Beach in May. Woods put the row behind him by going on the clinch his second Championship.
The form of Rory McIlroy has everyone puzzled. How can a man, whose play has been so serene over the past two years, suddenly look so erratic? Some say it's his new Nike clubs, other say it's a hectic personal life. Still, would you be all that surprised if he romped to victory as he did at Congressional two years ago?
Posting -16 in a US Open is just unreal. His nearest competitor was Jason Day, who was eight shots behind.
McIlroy is paired with Woods and Masters champion Adam Scott. That will no doubt be the featured group of the opening round, but will they get on course today?
Can Luke Donald, Lee Westwood, Ian Poulter or Justin Rose claim their first Major title here at Merion this week? This story gets trotted out at every Major, along with the same tired old cliches, like 'too good not to win one' etc. Still, it is a viable question, those players are among the 'best to have never won one'.
Defending champion Webb Simpson doesn't enter the tournament on the best of form. He hasn't won on Tour since lifting the trophy last year. A missed cut in the Memorial Tournament isn't the best way to prepare, either.
The players have made a decent effort to nip any talk of the rain making the course play easy in the bud. Of course it still presents a challenge, but there's no doubt that Merion is at its most challenging when dry and firm.
A statement from the USGA is imminent. We will keep you posted with all the latest happenings in Pennsylvania.
The skies are getting brighter and some fans are making their way back onto the course. Fingers crossed we get some play soon.
Merion is a short course, so much so that the fan capacity has been limited to 25,000. There is only two par-five holes on the course, at the second and fourth. Other than that, plenty of threes and short fours. Personally, I think this could be Luke Donald's week, but he'll have to rediscover his touch. Driving has never been his game, but he hasn't been himself on the greens of late either. And he's as good as anyone with a wedge or short iron in hand.
With the USGA being all in favour of evil pin positions, rare is it that the US Open is littered with low scores. Many believe that the winning score this week will be somewhere between eight and four-under-par. Since 2000, only two players have won this tournament with double-figures-under-par (Woods in '00 and McIlroy in '11). Geoff Ogilvy and Angel Cabrera won in 2006 and 1007 respectively with scores of five-over.
It looks like the rain has subsided somewhat, but still no announcement from the USGA.
From the European Tour's official Twitter page: "The rain has finally relented here at Merion, but it is a very wet course."
I would imagine that the bunkers will require some TLC, as will the greens. Graeme McDowell has already spoken of the horror of 'mudballs', but there's little you can do with fairways. As long as the traps and the greens (as well as surrounding areas) are clear of standing water, play on. Mudballs played havoc with the opening couple of rounds at last year's Masters, sending approach shots off on an alternate trajectory. Golf... she can be a cruel mistress.
Let's have a look at the pairings and tee times before play potentially resumes in Pennsylvania.
Rickie Fowler, Matteo Manassero and Jason Day got through two holes before being hauled off. That's a particularly exciting young bunch. Fowler has the ability to go low, while Manassero has been in excellent form of late. Jason Day will be looking to bounce back from heartbreak at the Masters, where dropped shots at the end of both his closing rounds cost him the green jacket.
The group behind them features 2009 PGA Championship winner Y.E Yang. He's playing alongside Fredrik Jacobson, who always seems to do well but never feature prominently in Major championships.
The South African contingent of Louis Oosthuizen, Charl Schwartzel and Tim Clark are on the fifth hole, while Sergio Garcia (E), Stewart Cink and Padraig Harrington (+1) are all on the fourth.
Sky Sports Golf on Twitter: "Play to resume at 5.10pm BST."
So we're just under one hour from the resumption of play. There's no indication as to where the lost time will come in, but I guess that'll be a judgement call for later in the day.
The range is open once again and the players are out practicing. We've had a false start, but hopefully the worst is behind us.
Bubba Watson (+1), Dustin Johnson (-1) and Nicolas Colsaerts (-2) were the second group out today. This course won't suit Bubba, I can't see him challenging for his second Major. Although, no-one really considered him for the green jacket in 2012, but did it. Dustin Johnson is another who is 'too good not to win one', but it's Colsaerts who has got off the the best start out of that grouping.
Phil Mickelson (E), Steve Stricker (-1) and Keegan Bradley (+1) went out after that group on the 11th. Mickelson and Stricker are playing in their 23rd and 18th US Opens respectively.
Luke Donald, Lee Westwood and Martin Kaymer are part of the afternoons groups beginning on the first tee, followed by Jim Furyk, Graeme McDowell and Zach Johnson. Then comes the feature group consisting of Tiger Woods, Rory McIlroy and Adam Scott.
It's important to remember, even at this stage of the tournament, that ties at the end do not mean a sudden-death playoff. Instead, the players go head to head in normal strokeplay over 18 holes on Monday, which is another reason weather breaks are unwelcome at the US Open.
The last US Open to go to a playoff was when Tiger Woods beat Rocco Mediate in a thriller at Torrey Pines in 2008. It was only the second time since the turn of the century that a playoff has decided matters, following Retief Goosen's two-shot victory over Mark Brooks in 2001.
Hats must be doffed to the ground staff at Merion. They have done a tremendous job of making the course at least playable over the past week, not just today. Bravo.
Right, as we edge towards the resumption of play let's give you the top of the leaderboard.
LEADERBOARD: (-3) Poulter; (-2) Colsaerts, Clark, Schwartzel, Hoffman; (-1) D. Johnson, Mahan, Stricker, Coetzee, Manassero, Palmer
Are you ready for some golf? Looking forward to an end to my time-filling waffle? We're about to get underway with Poulter on the 14th tee.
TRIPLE BOGEY! Keegan Bradley drops three shots at the 16th hole to slip to four-over-par. The early signs are not looking good for the 2011 PGA Champion.
Tim Clark (-2) hits a lovely shot into the 15th green to set up a birdie opportunity.
Stricker (-1) stands on the 17th tee and finds the green with a hybrid. Colsaerts plays from the drop zone at the 18th, and pitches a lovely shot to within a foot of the cup. Nice touch.
BIRDIE! Schwartzel chips in from the rough to get himself to three-under-par. It hit the hole at some pace but the flag took something off it. A bonus.
Tim Clark has missed his chance for birdie at the 15th, he didn't quite read the break. Mickelson follows Stricker onto the green with his tee shot at the 17th, but both have tough putts to make birdie. Poulter is in deep rough on the 14th and is weighing up his options, but he'll do well to make par from where he is.
Stricker leaves himself with work to do on the 17th green with his first putt, but Mickelson comes within inches of holing his. Unlucky. Meanwhile, Poulter gets the ball back into play on the 14th, but will need to be accurate with his approach to the green.
BIRDIE! Charley Hoffman (-3) has replicated Poulter by carding birdies on his opening three holes. Playing from the 11th certainly looks to be advantageous.
So three men now top the leaderboard in the form of Poulter, Schwartzel and Hoffman. The Englishman has found the green with his approach at the 14th, which gives him a chance of escaping with par following an errant tee shot.
BOGEY! Poulter (-2) leaves his putt on the 14th green out wide and drops out of the early lead. The ball threatened to break but ended up keeping a steady course.
Things have got off to a bad start for Sergio Garcia (+2). The Spaniard doubled the 14th and has now driven out of bounds on the 15th. Looks like that score will suffer further damage before he gets to the 16th tee.
BOGEY! Hoffman (-2) misses a par putt at the fourth, leaving Schwartzel out in front on his own. It looked like another misread putt that didn't quite break.
Snedeker plays a wonderful shot out of the green-side trap at the 17th. Stricker and Mickelson have both found the green at the 18th, but like the previous hole had left themselves a lot of work.
Stricker's putt this time is much better, but once again Mickelson goes closer. That should be par for both players.
Schwartzel finds the fringe at the back right of the par-three 17th, leaving himself no real chance of a birdie. Poulter sets up an opportunity at the 14th.
Garcia ended up scoring a quadruple-bogey eight at the 15th, meaning he is now on six-over-par through fives holes. Louis Oosthuizen is also down there on five-over through six holes.
BIRDIE! Great putt by Poulter (-3), as he reads the right-to-left break to find the cup on the 15th green and go back into a share of the lead.
PAR! Schwartzel's par putt at the 17th wobbles before dropping, meaning he stays level with Poulter at three-under par.
GREAT SHOT! Jason Day dials in his approach to the 15th, which should see him get to two-under-par.
BOGEY! Colsaerts (-1) tried a bump and run into the first green, but left himself with a tricky putt. It had the right weight, but not the right line, missing the cup to the left.
Poulter has found the green at the sixth with a seven iron, but Justin Rose (+2) misses a short putt at the 18th to card another BOGEY.
LEADERBOARD: (-3) Poulter, Schwartzel; (-2) Clark; (-1) Colsaerts, Hoffman, D. Johnson, Stricker, Coetzee, Palmer
MONSTER PUTT! Mickelson sinks for birdie on the first green to get to one-under-par. His putting so far today has been immaculate.
Clark knocks a birdie putt at the 18th close, which should see him save par. His countryman Louis Oosthuizen (+4) gets things moving in the right direction by draining his for birdie.
Poulter has left himself three feet for par at the 16th. Rose finds the green with his approach at the first hole (his ninth).
BOGEY! Schwartzel (-2) drops a shot at the 18th and leaves Poulter out in the lead on three-under.
PAR! Rose can't capitalise on a terrific second shot into the green at the first and can only make par. That leaves him on two-over after wasting a half-decent start.
BOGEY! Jason Day (-1) drops a shot at the 16th, missing with a three-footer to the right.
BOGEY! Dustin Johnson (E) also makes bogey, but he'll be happy with that after going out of bounds. Colsaerts saves PAR, while Bubba Watson makes BIRDIE. They were all great putts.
Mickelson (-1) went for the green in two at the par-five second, but he's found the green-side bunker. A good pitch out could leave him with a makeable birdie, though. Stricker (-1) has also found the trap, but he's missed to the right.
BOGEY! Poulter is now tied for the lead after dropping a shot at the 17th. He's on two-under with Tim Clark and Charl Schwartzel.
Stricker chops his ball out from the rough and leaves himself with around 15 foot for birdie, but Mickelson wows the crowd with a tremendous touch shot from the bunker, giving him a great chance to get to two-under.
Poulter misses with his approach to the 18th green and left out a sigh of exasperation after making contact with the ball. Matteo Manassero draws the cheers for a terrific shot from the bunker at the 17th.
MISS! Mickelson misses the opportunity to tie the lead at two-under. He takes a few seconds over his putt coming back and holds his nerve to remain one-under.
Sergio Garcia is now seven-over-par after a BOGEY at the 18th. Horrendous start.
Rose is finding it tough out there as he drags his approach to the second green wide to the right. Poulter makes a good recovery from the bunker at the 18th.
BOGEY! Poulter (-1) can't follow up his shot from the trap with a par putt and once again drops out of the lead, currently shared by Schwartzel and Clark on two-under.
BOGEY! Justin Rose hits a good putt but it just drifts by the hole, meaning he now drops to three-over.
Mickelson (-1) left himself in all sorts of trouble with his approach at the third hole, but once again showed his immaculate touch by pitching out from the deep, gnawing rough to leave himself with a makeable putt for par.
BIRDIE! Taiwanese amateur Cheng Tsung Pan has now tied for the lead, but how long can he stay there?
Stricker (-1) found the bunker with his shot into the third green, but it was wedged in an unplayable position. He dropped the ball in the rough and had a blind shot into the pin, but ended up pitching the ball a few feet from the cup. Good shot.
DOUBLE BOGEY! Stricker (+1) misses his putt and scores a double on the third hole.
EAGLE! Marcel Siem rolls one in from just off the green to jump from three-over to one-over.
Mickelson (-1) saves par at the third hole after a fantastic pitch from the rough, but Stricker (+1) ends up making DOUBLE BOGEY.
Rose (+3) hits his tee shot at the third into the heart of the green. Ahead of him, Mickelson lays up at the par-five fourth to give himself a wedge into the green.
George Coetzee (-1) is the only man on the top page of the leaderboard who started his round on the first hole.
BIRDIE! The 2003 Masters champion Mike Weir picks up a shot to move into a tie for the lead, alongside Tim Clark, Charl Schwartzel and Cheng Tsung Pan on two-under-par.
Mickelson drops his wedge short of the pin and the spin generated on these sodden greens takes it even further from the cup. He was far from happy with that one, was Lefty.
Sergio Garcia has carded birdie and eagle for his previous two holes and is now at four-over. How much more damage limitation can he do by the end of his round?
FIVE-WAY TIE! George Coetzee now makes it five tied for the lead with a birdie at the 11th.
A great putt by Mickelson isn't rewarded with a birdie. He left his approach well short of the cup, but almost sunk the putt. There wasn't quite enough on it as it curled just in front of the hole.
Poulter gives his birdie putt at the par-five second a chance of going in with a strong hit, but it missed a couple of inches to the right. He stays on one-under.
BIRDIE! Stricker (E) bites back from the disappointment of a double at the third by draining a long one for birdie at the fourth.
Mickelson (-1) hits his tee shot at the fifth and you can tell immediately that he doesn't like it. He shouts "miss it!" as the ball heads for a creek to the left of the fairway, but it doesn't listen to him and plonks right in some thick stuff.
Poulter (-1) steps up with a hybrid at the par-three third, but he's leaked it to the right.
conditions are easiest at Merion when the course is soft and wet, but the scoring at the moment leads one to believe that sunny skies over the weekend could see another over-par winner, which is not really that unusual for the US Open.
LEADERBOARD: (-2) Clark, Schwartzel, Weird, Pan (a), Coetzee; (-1) Mickelson, Poulter, Van Zyl, Phelan (a)
Great shot out of the bunker from Poulter. It was a deep one and he couldn't see the pin, but landed the ball inches from the hole. Good chance for par there.
BOGEY! Pan shoots five at the 16th to drop out of the lead. He is now on one-under-par.
Mickelson rattles in his par putt with aplomb. He pitches out from the thick rough at the green before finding the green with his third shot. Great save to remain one-under-par.
MONSTER PUTT! Rickie Fowler gets to even par by draining a 25-footer on the second green.
Poulter (-1) sinks his putt for par at the third and moves onto the par-five fourth now.
Tim Clark (-2) comes up just short as he tries for a birdie at the fourth, which would have seen him take the lead outright. Good effort.
Only 10 players in the field are under par for their round. It goes to show that the course hasn't been left defenceless by the heavy rains, as some (myself included) had previously thought. You never know, the conditions may be better for the afternoon groups.
Beautiful shot by Rose (+3) at the par-four fifth hole, as he pitches to within a few feet of the cup. Weir (-1) shoots five on the 18th, leaving Clark and Coetzee out in front on two-under.
Mickelson has been brilliant in and around the green so far, demonstrating that with another cute bunker shot. It's his driving that has been a nagging problem so far, but so far it hasn't cost him too dearly.
Lefty tidies up for par at the sixth, meaning his stays one-under and within striking distance of the lead. Clark (-2) has made a mess of the par-five fourth though, meaning that Coetzee (-2) could soon be the lone ranger at the top of the leaderboard.
Clark pitches his fifth shot at the fourth around 15 foot past the pin and spins it to the right, taking some of the yardage off the putt. That's still a difficult one for bogey though. Coetzee is on the 14th green but miles from the cup.
BOGEY! Coetzee pushes a putt wide of the mark and he drops back to one-under. He'll still be in the lead though, with Clark dropping at least one shot on the fourth hole.
DOUBLE BOGEY! A double it is for Clark then, and he drops to even par. Suddenly, it's a seven-way tie for the lead on one-under-par.
LEADERBOARD: (-1) Mickelson, Poulter, Coetzee, Schwartzel, Kelly, Stefani, Weir; (E) Mahan, Hoffman, Fowler, Van Zyl, Phelan (a), Pan (a)
NEW LEADER! Great play by Mickelson, as he stiffs his approach to the seventh to set up a fantastic opportunity for birdie, which he rolls in to hit the front on two-under-par.
Coetzee has a birdie putt from a couple of feet, but doesn't allow enough for the right-to-left break. The ball drifts just by the hole, so he stays on one-under-par.
BIRDIE! Colsaerts has got himself back to one-under-par with a birdie at the seventh hole. He's had to fight today after a great start saw him two-under before the weather forced the players off.
Mickelson (-2) finds the green at the par-four eighth hole, but will have to conjure a bit more of his magic on the dancefloor if he is to get to three-under.
BOGEY! Tim Clark's round has gone a bit south as a bogey at the sixth means he is now one-over-par. Poulter's second shot at the 13th left him with a tricky wedge into the green, but he's left himself with a makeable uphill putt.
Mickelson (-2) leaves his putt short and has a couple of feet left for par.
WHAT A PUTT! Jerry Kelly (-2) goes into a share of the lead with a snaking putt that went one way, then the other, before finally rolling into the cup. Fantastic read.
LEADERBOARD: (-2) Mickelson, Kelly; (-1) Colsaerts, Poulter, Stefani, Weir, Coetzee, Phelan, Colsaerts, Pan, Van Zyl
Colsaerts (-1) can't quite manage birdie at the ninth and stays one behind the leaders.
Poulter (-1) drags his tee shot into thick rough at the par-four sixth hole. His round has stopped and stuttered since the restart of play, when was three-under through three holes. Just one birdie and a few dropped shots since coming back on has took the wind from his sails, but he's scrambling to good effect.
Justin Rose had birdied the sixth and seventh to get himself to two-over-par. That's hopefully the start of a recovery before he finishes his round at the 10th.
Schwartzel (E) finishes short of the hole with his birdie attempt at the seventh. He was just on the fringe.
NEW LEADER! Phil Mickelson drops another long-range birdie effort to get to three-under-par on his own. Another fantastic effort from Lefty, he's going very well.
BOGEY! As previously stated, Poulter's round has faltered since the break for the weather. He drops another shot and is now level par through 13 holes.
Nicolas Colsaerts posts 69 for his opening round and is the clubhouse leader on one-under-par.
Poulter's round has turned into a disaster, as he now posts a DOUBLE BOGEY to fall to two-over-par. It's the story of his season so far.
Charl Shwartzel has fought to keep himself at level par, but he's still got three holes left to navigate. Hunter Mahan is also even, but he is on the 18th.
MONSTER PUTT! Fowler (-1) drops another one from distance! He is right in the mix here as he approaches the sixth hole (his 14th).
NEW CLUBHOUSE LEADER! Mickelson posts a three-under-par round of 67 to take the clubhouse lead from Nicolas Colsaerts (-1).
Jerry Kelly is on two-under-par with two holes left to play. Also at one-under and still on the course is Coetzee (15), Weir (11), Phelan (11) and Pan (10).
Click here to read the story of Phil Mickelson's opening round at Merion Golf Club. Will it be bettered this afternoon?
A slice of luck for Rose (+2) on his final hole (10), as his second shot cannons off the pin and hits a slope on the green before filtering back towards the hole. You take the shots where you can.
Poulter stiffs his approach to the eighth green. That's a great chance for a birdie to get him moving back up the leaderboard.
Justin Rose rolls in for his birdie at the 10th to finish his round on one-over-par. Tough day, but that's not a bad score at all.
BOGEY! Fowler (E) can't replicate his magic from long range as this time he pulls a putt wide of the hole from around five foot.
It's not long now until Tiger Woods, Rory McIlroy and Adam Scott - the world's top three players - tee off at the 11th hole. That's no doubt the highlight of this first round, but it's unlikely that they'll finish today.
LEADERBOARD: (-3) Mickelson; (-2) Kelly; (-1) Colsaerts, Weir, Phelan, Pan
Apologies, Poulter has just made BIRDIE to get back up to ONE-UNDER-PAR. He shouldn't be on the leaderboard below, but a manual refresh will do the trick.
Poulter has now found the green at the par-three ninth but has work to do for a birdie.
Tim Clark and Charl Schwartzel both post even-par rounds of 70. Their playing partner, and fellow South African, Louis Oosthuizen did not fare so well, finishing five-over-par. Ouch.
Bubba Watson, Dustin Johnson and Steve Stricker all shoot 71 to finish one-over, but disaster struck for Hunter Mahan at the 18th, as he carded a double bogey to finish two-over-par.
IN THE CLUBHOUSE: (-3) Mickelson; (-1) Colsaerts; (E) Clark, Schwartzel; (+1) D. Johnson, Watson, Stricker, Rose, Coetzee
Justin Rose is happy with his opening round of 71 at Merion. He said that he clawed it back at the end, telling Sky Sports News: "You can't win a US Open on the Thursday, but you can certainly lose one."
Jason Day (+1) comes up with a brilliant shot at the ninth hole to leave him with a good chance for a birdie. Meanwhile, Sergio Garcia finishes with a birdie to post 73. That's a great recovery from being six-over-par at one point, but still typically erratic from the Spaniard.
Jerry Kelly cards a DOUBLE BOGEY at last hole to finish even par for his round. That leaves Mickelson two shots ahead of Colsaerts heading into the afternoon groups.
BIRDIE! Donald (-1) gets off to a great start by picking up a shot at the first. He putted confidently from distance, reading the break superbly.
BIRDIE! Jason Day drops in for birdie to get himself to even par.
Westwood starts with a par at the par-four first.
An interesting side story to the pairing of the top three players is the uneasy relationship between Tiger Woods and Adam Scott's caddie Steve Williams. We all know the story, but I wonder what effect that might have, if any...
Ian Poulter shoots 71 to finish one-over-par. He's made a decent recovery after his round threatened to really spiral out of control. Charley Hoffman and John Huh have also joined the amassing group on one-over in the clubhouse.
Woods is the first to tee off in the featured group, but his opening gambit is errant and misses the fairway. McIlroy and Scott both hit fine shots that find the short grass.
GREAT SHOT! Luke Donald's third shot to the par-five second hole is a beauty, leaving himself with a fantastic chance to go two-under through two.
Westwood (E) misses a lengthy birdie putt at the second.
Scott's second shot into the 11th isn't a particularly good one. It finds the back of the green, and Tiger follows him on from the rough. However, the best shot was reserved until last, as McIlroy landed the ball above the in and spun is back towards the hole. Great shot.
Missed opportunity for Donald (-1), as he fails to capitalise on a great approach shot by missing the putt from a couple of feet. Keep your chin up, Luke.
Tiger's first putt is slightly misjudged, and leaves him with a tricky seven-footer for par.
SO CLOSE! Scott sends his putt up a slope and feeds it back down. It looks in all the way, but drifts agonisingly past the cup. Unlucky.
BOGEY! Well that's not the start Woods had imagined! He never looked confident over that putt, but makes the return for bogey.
MISS! McIlroy sends his birdie putt wide of the cup. Chance goes begging at the first hole.
Angel Cabrera is currently one-under-par through his first three holes, and Zach Johnson has birdied the first to join him.
BIRDIE! Donald shows his capabilities from distance on the green at the third to move onto two-under-par. He's done well to bounce back from his missed opportunity at the second.
Sweden's Peter Hedblom is now at two-under-par through his first three holes.
Woods and McIlroy have both found the fairway at the second, but Scott has leaked his to the left and into the rough. Woods did not like his approach as soon as he hit it and watched on as it flew into the green-side trap. McIlroy tries a draw but it's a wayward one.
Scott pitched out from the rough, leaving himself 140 yards to the pin. He too didn't catch the ball as he would have hoped, but the end result is better than his playing partners, with the ball resting on the fringe at the back of the green.
DOUBLE BOGEY! Graeme McDowell (+2) drops down the leaderboard with a double-bogey seven at the par-five second.
Defending champion Webb Simpson sets up a good chance for birdie on the par-four first hole.
Woods comes up with a brilliant escape from the bunker at the second hole but still has work to do for his birdie. Scott's birdie putt drifts wide of the hole and he has a tricky one left to save par. McIlroy chips from the rough, but he fluffs it.
Donald (-2) finds the green at the par-five fourth to leave himself with a chance for birdie. His putter is hot from this sort of distance, so he could be moving on up soon.
McIlroy rolls in for par, which should deliver a boost to his confidence. That wasn't the easiest putt. He's followed into the cup by Woods, who gets back to even par, from a similar distance.
McIlroy sprays a three wood way over to the left from the tee at the third. Scott steps up with an iron and lands it on the green for a great chance of a birdie.
Graeme McDowell has dropped another shot at the third hole to fall back to three-over-par.
A beautiful bunker shot from McIlroy has left the Northern Irishman with a few feet for his par at the third hole. Woods chipped from the green-side rough, but he lacked conviction and it fell well short of the hole.
MISS! The putt is sent past the hole and Woods drops back to one-over-par.
BIRDIE! Brilliant putt from Scott, as he moves to one-under-par. It was a slow break and a quickening surface, which bent from left to right and crept into the cup.
Donald hits a decent shot into the green at the fourth. He'll have a breaking 10-footer. Westwood is also on the putting surface looking for a birdie.
BIRDIE! Wow, brilliant putt from Westwood! That was from some distance, but he rattled it home to get to one-under! But it's bad news for Donald (-1), as he drops one to move back.
Estanislao Goya moves into second on his own on two-under with a birdie at the fifth.
Woods, McIlroy and Scott are all on the dance floor and the par-five fourth. Westwood booms his tee shot down the fairway at the sixth. Donald also splits the fairway, ending his ball a couple of yards short of Westwood's.
Tiger's putt at the fourth doesn't have the legs, but McIlroy's does and he moves to one-under-par. Scott (-2) pitched out from the bunker before rolling in for his birdie. Carl Petterson has picked up another shot at the third hole to join Goya and Scott in second on two-under-par.
WHAT A SHOT! Defending champion Webb Simpson (E) crushes a superb five wood into second pin to set up a great chance to move up the leaderboard.
Woods (+1), McIlroy (-1) and Scott (-2) approach the sixth hole, where Westwood (-1) has just hooked his approach into the crowd. He'd have that one back again.
Westwood gives himself a chance of making par with a neat chip from the side of the green at the sixth. Behind him, Scott drags his tee shot by the creek, ricocheting off a tree on it's way down.
Ernie Els is inches away from getting to two-under at the third, but there's not enough break to take it into the cup.
Woods chops the ball out of the rough, but there's a slight grimace on his face as if he's hurt himself - either that or he really didn't like it. The ball ended up at the back of the green and it'll be a difficult two-putt from there.
Westwood (-1) makes his par at the sixth to keep his round on track. Scott got out of jail with his tee shot, but still has plenty of work to do. McIlroy is on the green and to the right of the pin, around 10 foot from the cup.
The weather warning sign is back out at Merion, but nothing yet to suggest that there will be another interlude.
Scott's third shot into the par-four fifth isn't a great effort. That's a tough one for par. Woods chips from the fring at the back of the green but the ball hits a downslope, taking some of the pace off it. Very nervy start from the world number one, he doesn't look comfortable at all.
TIED FOR THE LEAD! Peter Hedblom has snook up the leaderboard. He's carded another birdie at the 16th to tie Phil Mickelson for the lead.
The crowd will McIlroy's putt towards the cup. It looked like it was tracking straight into the cup, but, like so many have today, it rolled past the hole.
WEATHER BUZZER! The klaxon sounds as Woods, McIlroy and Scott stand on the fifth green. It seems that the electrical activity above Merion is dangerous for the players and we're in for another delay.
The players make their way off the course, and once we're ready we'll provide you a definitive leaderboard and a recap of the action so far.
LEADERBOARD: (-3) Mickelson, Hedblom (5); (-2) Goya (7), Pettersson (4); (-1) Colsaerts, Donald (6), Westwood (6), McIlroy (4), Scott (5), Williams (5), Thompson (4), Els (3), Simpson (3), Stanley (2), Chappell (3), Donaldson (3), Pepperell (2), Points (3), Madsen (1), Grace (2); EVEN (Selected) Clark, Schwartzel, Kelly, Day, Fowler, Caberera (7), Stuard (7), Kaymer (6), Olesen (4)
Tiger Woods is one-over-par, but will make at least a bogey at the fifth hole when they resume play. McIlroy (-1) has a putt to save par on that hole, while Scott has already swallowed his medicine with a bogey to drop to one-under.
The world number one has struggled on the opening stretch of holes and a potential wrist injury only adds to his woes so far. Every good shot is followed by a couple of bad shots, and his accuracy off the tee hasn't been great. McIlroy has sort of muddled his way to one-under, but in a good way. He's done nothing spectacular, but he's there for the moment. Scott has played well but he has come up with a couple of loos shots of his own. It's been an intriguing start to the 113th US Open.
Luke Donald started off in excellent fashion by sinking a putt for birdie at the first. He was left frustrated by a missed opportunity at the second, but bounced back by picking up another shot at the third. A five at the par-four fifth, though, sees him sitting on one-under-par.
Word from the course is that the players are coming back out. Not a major delay then, which is good.
Westwood hasn't done too badly so far, either. He started with four pars before picking up his first shot at the fifth. At the next hole, he fired his approach into the crowd, but recovered well to save par and stay bogey free heading to the seventh.
The players are making their way onto the course now. Graeme McDowell enjoys a bit of banter with Rory McIlroy, despite being three-over through five holes. Not the best start for the 2010 champion.
Play resumes at Merion.
McIlroy finds the cup for par at the fifth to remain one-under-par.
BIRDIE! A fantastic chip from the rough by Westwood rolls into the cup and moves him onto two-under-par. Brilliant shot!
BOGEY! Woods sinks his putt for bogey at the fifth and heads to the sixth tee two-over-par.
Donald (-1) plays a nice chip into the sixth pin and has doesn't leave much for his par.
McIlroy finds the thick stuff with his tee shot off the sixth. Scott hooks his wide of the fairway as well, before Woods puts his in the short grass. Not the best display of driving from numbers two and three, but the number one shows them how it's done.
Hedblom has made a mess of the eighth, missing the fairway and now pitching into the green-side rough. That looks like it'll be at least one dropped shot to take him out of the lead.
Scott ended up in the bunker following his tee shot at the sixth, but has found the fairway with his second. An accurate wedge into the green will be needed to save par here.
Woods finds the green but is miles from the cup. McIlroy finishes not too far from Scott and will need to draw on his touch with the wedge to get the ball close to the hole.
BOGEY! Hedblom minimises the damage by dropping just the one shot at the eighth. It became a bit a toil after finding the rough with he tee shot.
MISS! Westwood leaves a putt out to the right on the eighth hole, which would have seen him move into a share of the lead on three-under-par. Fear not though Westwood fans, he's playing as good as anyone out here.
Scott puts his approach close to the cup but McIlroy goes a bit longer. It's makeable for the Northern Irishman, but his Australian counterpart will have a gimme to save his par.
BIRDIE! Amazing! Woods (+1) winds in a monster putt at the sixth to get his round moving back in the right direction. Has that break helped in any way? And could that be a pivotal moment in his first round?
McIlroy ended up making bogey on the last hole, meaning he is now on level par. All three players have found the fairway on the short par-four seventh, though.
WHAT A SHOT! Simpson works the ball into the sixth green from the left, and starts walking as soon as he's hit it. He likes it, and so he should, as it hits the right of the green and feeds around towards the hole. Great shot.
Scott lands his approach on the green, ending around 15 foot from the cup. Woods stops his a bit closer, with just a little bit of bite on the green. McIlroy digs his shot out with a low wedge, finishing a similar distance to his playing partners but on the other side of the hole. All three now have birdie opportunities at the seventh.
Westwood and Simpson both miss opportunities to tie the lead at three-under-par.
BIRDIE! MacIlroy sinks his putt on the seventh green to move back onto one-under par. Scott's effort finishes short and he taps in for par.
Donald lands his ball safely on the fairway at the 10th.
Woods stays at one-over-par as his chance goes begging at the seventh. Westwood finds the front of the green at the 10th and will have a putt for eagle, but you fancy him to make at least a birdie. He's going well so far!
Terrific wedge shot into the eighth green by Tiger Woods! That's a great chance for a birdie to draw him level par. Donald catches a break with his second into the 10th, hitting a downslope before finishing in the middle of the green.
Westwood rolls his eagle putt next to the hole and that should be a birdie to grab a share of the lead.
Scott and McIlroy also find the green at the eighth, although the Northern Irishman is much further away from the hole. He was playing out a divot though, which made it extra tricky.
Simpson is playing beautifully as well as another birdie chance approaches at the sixth.
TIED FOR THE LEAD! Lee Westwood joins clubhouse leader Phil Mickelson on three-under-par with a well-plotted birdie at the par-four 10th. He went for the green off the tee and was rewarded for his strategy, two-putting to pick up another shot.
BIRDIE, MISS! Scott (-2) rolls his putt into the centre of the cup, but Woods (+1) messes his up from a similar distance.
Scott finds the back of the par-three ninth green with a smooth five iron. McIlroy is next up, also with a five iron in hand, and he too is looking at a birdie putt. Woods comes up short and to the right, although still on the dance floor.
Great second shot by Donald (-1) into the par-four 11th.
Westwood (-3) is also on the green in two at the 11th, but his putt has some distance to travel.
His putt didn't have enough on it and comes up short of the hole, but he should tidy that put for par. McIlroy (-1) also comes up short at the ninth, but Donald has converted his to move up into a tie for second on two-under-par.
Scott (-2) settles for par, but Tiger (+2) sends his putt well past the hole, leaving himself with a tough five-footer to save a shot, which he can't do. It's another step backwards for the world number one.
McDowell (+1) has gone BIRDIE-BIRDIE at nine and 10 as he looks to shake off a poor start. Two very good putts and he looks like his blade is starting to warm up now.
Scott's tee shot at the 10th skips off the fairway and into the rough. McIlroy's takes the same line, but his ball lands on the fairway. Woods goes at it with an iron, but like Scott he finds the rough with one bounce. Depp stuff, that.
LEADERBOARD: (-3) Mickelson, Westwood (11); (-2) Donald (11), Goya (9), Hedblom (9), Scott (9), Simpson (6); (-1) (Selected) Colsaerts, McIlroy (9)
Good shot from Tiger to leave himself with an uphill putt after finding the rough with his tee shot at the 10th.
So unlucky for Westwood! His approach to the 12th green hits the wicket basket, which top the pins at Merion, and cannons well off the green.
Scott's approach at the 10th creeps just behind Tiger's ball, which should give the world number one a decent read for his putt.
The Aussie pulls his left-to-right putt wide of the hole and rolls in for par, which keeps him at two-under-par. Tiger up now...
Actually, it's McIlroy to go next. He catches the ball cleanly, but gives too much allowance for the break, but will have a tiddler for par.
Bad luck costs Westwood two shots at the 12th, and he moves back to one-under-par, leaving Mickelson out on his own at the top on three-under.
However, Luke Donald rolls his putt in for birdie, which once again ties the lead. These Englishmen will just not leave Mickelson alone. The American is sitting pretty in the clubhouse, though. Still a long way to go for these two out on the course.
It's the par-three 13th next for Donald and Westwood, the most hole-in-one-able hole on the course. Both men find the green with their tee shots.
Scott (-2) hits a lovely shot into the 11th green, showing Tiger (+2), who found the rough, how it's done.
McIlroy finds the green, but he's some distance from the cup. Big news from the 13th, though...
NEW LEADER! Luke Donald rattles home from five foot to take the lead on four-under-par!
That looks to be that for the first day of the US Open with the opening round to be finished tomorrow. McIlroy ended with a bogey, which drops him back to even par, while Woods will have a putt first thing in the morning. Scott cards a birdie to tie Mickelson on three-under, one behind the leader Luke Donald.
LEADERBOARD AT THE END OF DAY ONE: (-4) Donald (13); (-3) Mickelson, Scott (11); (-2) Simpson (8), Goggin (6), Presnell (5); (-1) Colsaerts, Westwood (13), Goya (11), Hedblom (11), Williams (10), Pettersson (9), Alker (6), Brown (4), Hall (5)
Well Luke Donald tops the leaderboard at the end of day one, but with five holes of his first round still to play. Phil Mickelson, Adam Scott and Lee Westwood have looked good so far, as has defending champion Webb Simpson. It'll be a long day tomorrow though, so join us earlier than expected at 1.30pm UK time.
Thanks for joining us throughout today and hope to see you again tomorrow!
