Old friends Steve Clarke and Roberto Di Matteo were in opposite dugouts this afternoon as Chelsea visited West Bromwich Albion.
The Baggies produced another fine home display to claim the scalp of the European champions, with Shane Long and Peter Odewingie scoring the goals in a 2-1 win.
The win moved West Brom to the lofty heights of fourth place in the Premier League, just a point behind the Blues, who could be six adrift of the top of the table by the end of play today.
Read how Di Matteo suffered defeat against his former employers below.
So, first things first - team news, and there is some interesting selection decisions from the Chelsea camp.
The much-hailed attacking midfield three of Hazard, Mata and Oscar has been broken up with the omission of the latter two.
Victor Moses and Daniel Sturridge are handed rare starts in their place. Mata and Oscar are dropped to a bench that also includes Ramires and Marko Marin.
Branislav Ivanovic and Ashley Cole are also among the subs, suggesting that Di Matteo has an eye on their crucial Champions League tie with Juventus in midweek.
Full Chelsea team: Cech; Azpilicueta, Cahill, Luiz, Bertrand; Romeu, Mikel; Moses, Hazard, Sturridge; Torres
And the Blues subs: Turnbull, Ivanovic, Cole, Ramires, Oscar, Marin, Mata
Bold tactics from Di Matteo to rest players for the trip to a West Brom side that have been so impressive on their own patch.
Much of that success has been down to the counter-attacking threat of forward pair Shane Long and Peter Odemwingie. Both start for the Baggies, with loan striker Romelu Lukaku ineligible to face his parent club.
In midfield, Clarke opts for Zoltan Gera rather than Chris Brunt on the left wing. The in-form James Morrison will provide a goalscoring threat from the other flank.
At the other end of the pitch, Boaz Myhill continues to deputise for Ben Foster, who is still absent with an ankle injury. Jonas Olsson witnessed the Zlatan Ibrahimovic show from up-close on Wednesday and captains West Brom this afternoon.
The Swede is partnered in central defence by Gabriel Tamas, who replaces the injured Gareth McAuley.
Full West Brom team: Myhill; Jones, Olsson, Tamas, Ridgewell; Morrison, Yacob, Mulumbu, Gera; Long, Odemwingie
And the Baggies subs: Daniels, Reid, Popov, Rosenberg, Brunt, Dorrans, Fortune
Of course, Chelsea are without skipper John Terry, whose projected three-week absence is much shorter than initial fears suggested after his concerning collision with Luis Suarez last weekend.
Less than 10 minutes to kickoff now and I'm looking forward to this one. Chelsea's team selection has given the match an extra edge as I now rate each team's chances equally.
I am interested to see how Ryan Bertrand fares today. With more rumours about Ashley Cole's future surfacing this morning, the youngster could be Chelsea's long-term left-back solution.
Some interesting quotes from Steve Clarke on his opposite number and former Chelsea teammate: "When I played with Roberto I didn't see him as a future manager. When I was coaching the youth team at Chelsea, he suddenly turned up one day and was standing by my side wanting to know what I was doing."
We are underway at the Hawthorns...
Good, strong tackle from Romeu on Claudio Yacob. The Spaniard is another who has benefited from Di Matteo's rotation this afternoon.
Sturridge is starting his first Premier League game of the season and will certainly be keen to impress. He won't with shots like that though, as he drags an ambitious 30-yard effort well wide of Myhill's goal.
The personnel switch made by Di Matteo means that Eden Hazard is operating from the right side, with Victor Moses occupying the Belgian's usual left-flank berth.
OFF THE LINE! Chelsea get in behind the Baggies defence for the first time courtesy of Moses, who cuts the ball back for Bertrand to shoot. Liam Ridgewell is alert to the danger and gets back to his goal-line to clear.
In the same incident, there was also a half shout for a Chelsea penalty but the Michael Oliver adjudged that Hazard's follow-up effort was not blocked by a West Brom arm.
GOAL! West Brom 1-0 Chelsea (Shane Long)
GOAL! Poor defending from Chelsea down the right as Morrison is found unmarked on the left edge of the area. The Scot delivers a precise cross over the head of David Luiz, who Long had managed to wriggle free from before heading past Cech. Chelsea have a real game on their hands this afternoon!
More reason to cheer for the home fans, but these are ironic cheers as Moses, after running down the left, completely misses the ball when attempting a cross and falls flat on his face. One for the Christmas bloopers dvd.
John Obi Mikel has never scored a Premier League goal, so imagine Sturridge's frustration when the Nigerian opts to shoot rather than play him in on goal. Mikel connected reasonably well with the shot but it was always drifting wide.
Poor defensive header from Billy Jones sees the ball drop at the feet of Moses. His run-and-shot has the same result as Sturridge's earlier effort. Well wide.
Di Matteo this week revealed his admiration for reported transfer target Radamel Falcao. Fernando Torres has barely had a touch so far, and I am sure he will be dying to prove his manager should not be in the market for a replacement striker.
Good work from Azpilicueta on his own byline as he pokes the ball away from Liam Ridgewell and starts a Chelsea counter attack.
Long gets a strong ticking off from referee Olivier after crunching David Luiz from behind. The Irishman was fortunate to get away without a caution there.
Excellent hold-up play from Long as he chest controls a punt forward and lays it back to Odemwingie. That pair have starred for West Brom on the counter attack this season but get no joy on this occasion as Chelsea get men back behind the ball.
Chance for Chelsea! Best Chelsea attempt of the match so far as a headed clearance falls for Sturridge to hit first time. He connects well and surprises Myhill by taking the shot on early, but the Welshman gets down to gather comfortably in the end.
Chance for WBA! Straight down the other end, Long is denied a second by a goal-saving tackle from Gary Cahill. Morrison finds Billy Jones in plenty of space on the right and his low cross is straight into the path of Long, but Cahill stretches out a leg to get to the ball first. The goalscorer wants a penalty, but Cahill got all of the ball there.
Chance for WBA! This time Long gets the better of Cahill, again showing great strength with his back to goal to shrug off the England international defender. He cuts inside from the left and unleashes a low shot that goes narrowly wide of Cech's post.
GOAL! West Brom 1-1 Chelsea (Eden Hazard)
GOAL! Hazard's initial misdirected cross falls to Azpilicueta, who cuts back onto his left foot and drifts a cross in for Hazard to head in at the back post.
After showing very little in the opening 35 minutes, Chelsea are bouyed by Hazard's equaliser and nearly go ahead as Sturridge hits another first-time volley from Torres's headed knockdown. The shot had power behind it but fortunately for Myhill was narrowly off target.
Corner for Chelsea as Luiz's free kick is deflected off the wall and behind.
Chance for Chelsea! Romeu heads the ball back into the box after Chelsea's second corner is cleared. It falls to Cahill, who shifts the ball to Torres to pass on to Moses. Sturridge is unmarked at the back post but the former Wigan man instead rashly opts to shoot and his strike flies over the crossbar.
HALF-TIME: West Brom 1-1 Chelsea
HALF-TIME: On the balance of play, this is probably a fair scoreline at the break. West Brom took the lead through Shane Long and then enjoyed the majority of the possession and chances until the half-hour mark. Eden Hazard's switch back to his preferred left-wing position seemed to result in more effective Blues attacks and it was the Belgian who earned Chelsea parity with a back-post header. The visitors then had the better opportunities as we approached the interval, but could not beat Boaz Myhill for a second time.
Coincidentally, 1-1 is my SkySports Super6 prediction. So I'll have my fingers crossed for no more goals in the second period!
Read Sports Mole's half-time report on the contest here.
The action has resumed at the Hawthorns...
Immediately, Chelsea are showing their intentions as Bertrand fizzes a low cross in which Ridgewell is forced to turn behind for a corner.
GREAT SAVE! Sturridge tests Myhill with a powerful shot from inside the area which the Welshman parries to safety.
Beautifully whipped ball in from Azpilicueta is just over Torres's head and Tamas nods the ball away.
GOAL! West Brom 2-1 Chelsea (Peter Odemwingie)
GOAL! There goes my Super6 hopes! West Brom regain the lead and it is the third headed goal of the afternoon. Lovely build-up play from the hosts as a patient move eventually comes to Long on the right. He puts the ball in towards the near post and Bertrand had lost Odemwingie, who angles the ball past Cech.
Chelsea nearly reply instantly as Azpilicueta's controlled first-time cross seems destined for Sturridge at the back post. However, Olsson is on hand to stretch out a leg and prevent the Englishman from levelling the scores once again.
As his players respond on the pitch, Di Matteo is reacting to going behind in the dugout, signalling for Mata and Oscar to warm-up.
Very brave goalkeeping from Myhill as he risks taking a boot in the face to pounce on the ball which was about to be fiercely struck by Moses six-yards out.
Odemwingie sends a free kick from a promising position straight into the wall.
The introductions of Mata and Oscar are imminent. Superstition dictates that Di Matteo wait until after this Blues corner to make the changes.
DOUBLE CHELSEA SUBSTITUTION: Here we go then. Mata and Oscar are on in place of Romeu and Fernando Torres, who has had another miserable afternoon in a Chelsea shirt. He has been almost anonymous, and thus the Falcao rumours will continue...
Sturridge has got his wish and is now playing through the middle. Mata is immediately on the ball and chips a pass through to Sturridge, who beats the offside trap but cannot flick his header goalwards.
Chance for Chelsea! More brilliance from Mata as he dinks a ball over the home defence and Sturridge is again the target. He stretches and gets the slightest touch on the ball, but not enough to seriously trouble Myhill.
Mata has only been on the pitch for five minutes and already he has twice opened West Brom up. Nothing from Oscar yet though, but I'm sure we won't be waiting long for him to have an influence...
Shot! Yacob tries his luck from distance and gets all of the ball, but it is straight at Cech, who gather at the second attempt.
DOUBLE WBA SUBSTITUTION: Steve Clarke turns to his bench for the first time, but these are not defensive substitutions. Chris Brunt and Graham Dorrans come on to replace James Morrison and Zoltan Gera in midfield. Fresh legs probably the thinking from the Baggies boss.
Nearly magical from Long, whose attempted back-heel return to Mulumbu is just intercepted by the toe of Gary Cahill.
Corner to Chelsea. They go short to Mata, who crosses into the box but Jones makes the headed clearance.
That double change from Clarke has set West Brom up perfectly to play on the counter. Long and Odemwingie will continue to do what they do, while the fresh duo of Dorrans and Brunt will provide the support.
SUPERB SAVE! Mata and Sturridge again combine as the Spaniard plays in his teammate, who runs away from Tamas and then shoots from 10 yards out. The effort is going across Myhill but he gets a strong hand and denies Sturridge an equaliser. Cracking stop.
WBA SUBSTITUTION: The excellent Long is relieved for the last 10 minutes and replaced by Marcus Rosenberg.
CHELSEA SUBSTITUTION: Di Matteo turns to his star-studded bench for the final time as Ramires comes on for John Obi Mikel - leaving Chelsea without a genuine defensive midfielder. All-out attack is the message from Di Matteo.
Concern for Steve Clarke as Youssouf Mulumbu pulls up with an apparent hamstring injury. The hosts have already made three changes...
Shot! A clearing header falls to Hazard, who chests the ball down and hits a left-foot volley. Tamas charges out and partially blocks the effort, which is eventually collected safely by Myhill.
Fortunately for West Brom, Mulumbu seems fit enough to play on during the last five minutes. It is a good job too, as seeing out Chelsea in the latter stages is difficult enough with 11 men.
WHAT A CHANCE! That could have been the moment. Genius stuff from Oscar, who sends a delightful first-time flick into the path of Sturridge. He strikes from a tight angle inside the box, but the ball finishes the wrong side of the post from the Chelsea perspective.
We are now entering stoppage time at the Hawthorns, of which there will be four minutes.
Everyone is forward for Chelsea, and I mean everyone. Cech gets permission from his manager to venture up for the corner and Mata's cross nearly falls for him on its way behind for a goal kick.
Less than a minute remaining on the clock, and West Brom are playing keep ball deep in the Chelsea half.
FULL-TIME: West Brom 2-1 Chelsea
FULL-TIME: Superb result for West Brom, who continue to prove formidable at home. Long and Odemwingie headers either side of Eden Hazard's own nodded effort earned Steve Clarke a win over the club he represented 300+ times as a player. The result means it is no win in four league games for his ex-Blues teammate Di Matteo, who may now be regretting resting so many big names.
Read Sports Mole's full-time report on the contest here.
That is all from me this afternoon! Be sure to stay with Sports Mole for live coverage of of Norwich vs. Manchester United this evening. Over and out...