Hello football fans! The World Cup continues today with the final two games from the second round. Six teams are already in the quarter-finals, and up first Argentina and Switzerland will be looking to become number seven.

As we have already seen with France and Germany just scraping through respectively yesterday there is no such thing as an underdog at this stage of the tournament. Switzerland, of course, are ranked sixth in the world so Argentina will need to be at their best if they are to make the last eight.

The teams are in here at SM, so I'll get the XIs right over to you. Hold your breath...

ARGENTINA XI: Romero; Rojo, Fernandez, Garay, Zabaleta; Gago, Mascherano; Di Maria; Higuain, Messi, Lavezzi

SWITZERLAND XI: Benaglio; Lichtsteiner, Rodriguez, Schar, Djourou; Inler, Behrami; Xhaka, Shaqiri, Mehmedi; Drmic

SUBSTITUTES:

Argentina: Andujar, Orion, Campagnaro, Demichelis, Basanta, Biglia, Perez, Maxi Rodriguez, A.Fernandez, Alvarez, Palacio

Switzerland: Sommer, Burki, Senderos, Lang, Ziegler, Fernandes, Barnetta, Dzemaili, Stocker, Seferovic

so there's just the one change from Alejandro Sabella following the thrilling 3-2 win over Nigeria last time. Ezequiel Lavezzi comes into the attack to replace the injured Sergio Aguero and will join Messi and Gonzalo Higuain in a frightening front three.

Ottmar Hitzfeld makes no changes to his XI from the 3-0 win over Honduras. He has no reason to, of course, as they were thoroughly impressive in that game. This is a massive step up for them, and last time they played a top level opponent they lost 5-2 to France in the group.

In that game Xherdan Shaqiri announced himself as the superstar of this Swiss side with a brilliant hat-trick - in particular his first goal from 25 yards. He does not often get to be the star at club level, surrounded by the likes of Arjen Robben and Franck Ribery, but he looks to be enjoying his time so far at the World Cup. He will be key if the Swiss are to upset the odds.

Argentina and Switzerland are matched up for the Round of 16. Which team will prevail? Check the facts & stats here: pic.twitter.com/YE0xLGfxWg — SBOBETweets (@SBOBETweets) July 1, 2014

Argentina's key player, of course, needs no introduction. His ability to translate his club form to the world stage has often been questioned, but he has well and truly proved the doubters wrong so far. From Argentina's three games, he has four goals and all from just seven attempts. If he is at his clinical best, then Switzerland in truth have little chance.

Hitzfeld had some bad news yesterday with his brother passing away. He will bravely continue on what is one of Switzerland's biggest games ever, and he will certainly not want this to be his last game now. Remember, he retires after this World Cup - can he keep it going?

The Swiss coach has 19 trophies in his career so far but winning the World Cup with his current side would surely go down as his greatest achievement. Very unlikely, of course, but you really do never know with some of the results we have seen so far. Costa Rica are in the quarters, so why not Switzerland?

There have already been several goals that will be in contention for the best of the tournament - as well as more already scored than four years ago in South Africa. Messi, with his text-book free kick against Nigeria, and Shaqiri's effort against Honduras are two of the better ones to have been scored. There is plenty in both attacks this evening.

No team has created more chances per game at the World Cup than Switzerland (15). Argentina are on 13.67. #SUI #ARG pic.twitter.com/uuMbEn7Vvp — Squawka Football (@Squawka) July 1, 2014

That last statistic is quite impressive. For all Hitzfeld is lauded as an excellent defensive coach, he has unlocked plenty of attacking potential in his side so far. As well as Shaqiri, Josip Drmic up front is an excellent player and is just the sort of striker - strong, intelligent - who can act as a foil for the creative Bayern man. There are goals in this Swiss side, and the Argentina defence is certainly not the quickest.

They also have one of the better full-backs around, in my opinion, in Ricardo Rodriguez. Not only is he bullish and strong as an ox at the back, but his delivery from set pieces is brilliant. He and Pablo Zabaleta vying for control of that flank will be a very interesting battle to witness.

The players are on the pitch and the national anthems are just beginning. Some boos from the sections of the Brazilian support for Argentina's. Plenty of blue and white shirts in the crowd as well, who quickly drown out any dissent.

There have not been a great deal of goals in the knockout stage so far - at least in the 90 minutes - but this one promises much. There have been plenty shared between the two teams up to this point and, well, just look at that Argentina front three.

KICKOFF: Argentina, in their traditional light blue and white, get things underway here. This should be good!

Plenty of early bite from Switzerland, who are pressing Argentina high at the moment. Lavezzi is taken out there by a nasty one from Shaqiri, but he's up and there was no card. Argentina seeing most of the ball so far.

It's a lovely day for football in Sao Paulo - perhaps more for watching than playing, due to the heat, but the sun is beaming down nonetheless. Angel di Maria is tugged back by Stephan Lichtsteiner and he wants the Swiss player booked, but the referee decides it's too early.

First real foray forward there for Switzerland, with Shaqiri linking up well with Mehmedi, whose cross is partially cleared. The Bayern man then does well to win a corner and thus a chance for the men in red... but Gokhan Inler's shot from 30 yards is well over. He can certainly score from there, but not this time.

Johan Djourou just produced a fine headed clearance, but then almost got his side in real trouble with a sliced one straight to Higuain. Those couple of minutes is Djourou in a nutshell - he's always capable of errors that could prove costly.

Plenty of movement up front at the moment for Argentina. The Swiss defence are very tight to Messi and are closing him down at every opportunity, which is actually leading to a bit of space for Higuain. There isn't just one dangerman in this Argentina team, so Switzerland have to be careful.

There have been no chances as yet in what has been a very tactical opening 15 minutes or so. Argentina have had more of the ball, but the Swiss threat has been mainly down the left early on. Zabaleta has had just the one chance to cross, but only succeeded in picking out Diego Benaglio.

That was the first sight really of Messi, who drove down the right before taking on two defenders and getting into the box. In the end, however, he was just crowded out and the chance went, but his turn of speed on the ball is so impressive.

Messi is technically playing on the right, but is linking up with the midfield in the middle quite often in order to get involved in the game. The crowd have gone a little flat after what has been a slightly disappointing start to the game. Di Maria is brought down, for about the third time, some 30 yards from goal on the right side.

Messi clipped it into the near post area, with Higuain glancing the header over the bar. It was a very hard chance, as he head to stoop and nod it behind him, and he'd have done very well to hit the target from there. That one can't quite go down as a chance.

CHANCE! Shaqiri wins a corner, this time on the right. His free kick was cleared back to him, and he worked the next set piece off the legs of Fernando Gago. They win another and Shaqiri cuts back to Granit Xhaka, whose shot tested Romero with a low save with his legs. A better strike there and that could have been the opener.

CHANCE! It has come into life now. From Di Maria's ball in Lavezzi meets Higuain's knock-down and works Benaglio. It was a snap-shot and he just did not get the right amount of power on it.

Argentina are starting to up the pressure a bit, with a lot of possession in the Swiss half. The team in red are doing a good job of keeping things tight off the ball, however, and Argentina are struggling to work much where it matters.

Lavezzi is a bit lucky to escape a booking there as he clatters Shaqiri on the Swiss right. Up come the big men from the back as the Bayern men steps over this set piece. Could be dangerous.

BOOKING: Finally the referee does go to his pocket, and it's for Xhaka who got in the way of Di Maria as he tried to get past. That's probably his first offence, but the referee has seen enough in what has been a tense game.

CHANCE! What a chance for Switzerland! They break, with Shaqiri flicking a superb pass in front of Drmic. Romero decides not to come for it and the striker somehow chips it right into his arms! Do better there, he has to do better!

That chance for Drmic was by far and away the best of the game and it really should be 1-0 to the Swiss. Argentina are finishing strongly but just cannot work a chance like the one Drmic just missed.

It's finely poised here, but Switzerland might well have been ahead after Drmic squandered the best chance of the game by far. Really, it was the only genuine chance as this has all been a little disappointing so far.

Most of the Argentinian attacking players have been kept quiet so far, which is exactly what Switzerland set out to do. Messi has been crowded out and, although Higuain has been allowed space, it has not been in the positions that he can cause the most threat - i.e. in the box. So far, so good for Hitzfeld's side.

Something needs to change for Argentina, that is for sure. Lavezzi has run plenty, as has Di Maria, but neither player has had much of a say in an attacking sense. The PSG man did have their best chance, but it was not much of one with a snap-shot half-volley from inside the box.

KICKOFF: We are back underway here then. Will we see a goal in the second half?

Foul from Xhaka there on Di Maria, and the referee could well have given him a second yellow. He gets one final chance, however. He cannot do that again.

Now the Swiss have a free kick at the other end in a similar spot, as Mascherano brings down Lichtsteiner. Shaqiri, as always, stands over it. It's just about in shooting range, but a cross is the better option.

SAVE! I thought he might, and Shaqiri did indeed go for goal. Romero keeps it out and then almost fumbles out for a corner, but survives. He hasn't been too convincing so far, the Argentina stopper.

Very ambitious from the left-back Rodriguez. It was a rare foray forward from the Wolfsburg man, and his strike from 30 yards went wide of the far post.

Lots of possession on around the half-way line for Argentina, but they're really lacking in ideas. It's a worry for them, as Switzerland have shown plenty and probably just about deserve to be leading.

What is Di Maria doing! He skins his man on the right and for some ridiculous reason attempts a Rabona and crosses it out of play! Incredible decision and he should be hauled off immediately.

SAVE! Argentina are still seeing a lot of the ball, and that's more like it from Rojo. He whips in a great ball from the left, and Higuain's header is tipped over by Benaglio - good effort.

Switzerland have a chance to break, but Inler for once is very wasteful with the ball. He has Mehmedi marauding down the left, but instead tried to find Drmic and it was all too easy for Fernandez to intercept.

SWITERLAND SUB: Xhaka, who has been walking a tightrope since being booked, makes way for Gelson Fernandes. They shouldn't lose any steel in the midfield with that change.

CHANCE! Decent chance with his head for Higuain, but he did not get enough on it and glanced it on. It's worked back to Messi, who shot from 20 yards but his effort was fizzed just over. Argentina are just upping the gears here.

There are not many candidates, but this so far must go down as the worst match of the tournament. Excellent defending there from Rojo, who was then tugged back by Drmic as the Swiss player tried to get past.

Switzerland have been patient, waiting for Argentina to try to create something. They now get a chance to break, with Fernandez in the end in well on Mehmedi to tackle. They don't work anything from the chance.

BOOKING: Fernandes's first act of the game is to rip through Di Maria as the winger looked to break. He has absolutely no complaints about the yellow card. Meanwhile, Lavezzi makes way for Rodrigo Palacio.

CHANCE! Palacio gets an immediate chance there from Messi's clipped ball from the corner of the box. Both he and Higuain want it, but in the end the sub nods it wide of the far post. This looks for all the world like a 0-0.

SAVE! Messi probably should have scored! He gets the ball on the edge of the box, goes past a tackle and shoots low but it was well kept out by Benaglio, who is then clattered as Palacio comes in for the rebound. Brave goalkeeping, but he looks hurt now.

Argentina are still looking to press as we enter the final 10 minutes. Messi tries to take things into his own hands with a run from 30 yards, but he was crowded out before he could shoot. Could this be yet another period of extra time? It looks likely.

SWITZERLAND SUB: Haris Seferovic has come on for Drmic here. He has one late winner to his name against Ecuador, can he grab another?

Rojo wants to be the hero there as a cross is cleared as far as him, but his shot from an angle 25 yards out was always flying over the bar. Just five minutes for a goal or we're heading to extra time.

Messi might have gone into the book for shoving Valon Behrami to the ground. In fairness to the referee, the Swiss midfielder made a meal of the contact.

BOOKING: Wonderful from Messi, who gets the ball on the left, glides past three but his pass to Palacios is just cleared behind for a corner. From it the Swiss break through Rodriguez and is then tripped by Rojo. The Argentinian player is then shown the yellow card and rightly so.

There will be three minutes added on at the end of this game, as Schar meets a free kick but heads it over.

The good news: that's over. The bad news: there's 30 minutes more of this. Woeful does not even cover what we have witnessed here this evening.

Switzerland have done what they have needed to, really. The onus was on Argentina with their attacking talent to score, but they couldn't The players are back out and we're almost ready to go again.

Here we go then, extra time is underway. I fully expect Argentina to do a Germany and score right at the start when they could have won it just five minutes ago.

Messi knows where he likes to operate: http://t.co/5iTAhtDhCB #ARGvsSUI pic.twitter.com/lYQnj1Xk5M — ITV Football (@itvfootball) July 1, 2014

Mascherano brings down Shaqiri some 30 yards out, with Inler standing over it to swing it in. This is dangerous if they get it right.

Neither side has created a chance yet in this opening period of extra time. Teams just don't seem to want to win these knockout games, which is a real shame as there should have been goals in this one.

The ball is given away all too easily there by Garay, but Seferovic decides to hit his shot from 25 yards and it cannons into a defender from close range. Brief excitement there, but it quickly faded.

The Swiss are finishing the half stronger here, but they just cannot get into the Argentina half. Schar wins a throw and tries to boost the crowd in the corner, which contains a huge section of Brazil fans cheering on Switzerland.

ARGENTINA SUB: Rojo, suspended for the next game, might have made his last appearance in Brazil as Basanta is on for him.

All I can say is that I hope this at least goes to penalties having endured all this. A shootout never lacks in excitement, right? Lucas Biglia comes on now for Gago - are Argentina playing for penalties now?

We are back underway for the final time today. The atmosphere is so tense now, this could be a huge 15 minutes for one of these teams.

SAVE! Really good strike there from Di Maria, who shoots from the corner of the box but Benaglio does well to tip it around the post for a corner.

Di Maria is finally starting to have an impact, and he shoots again but this time it is deflected behind for a corner off Djourou. Nothing comes from the corner and on comes Blerim Dzemaili for Mehmedi.

Just five minutes now until penalties and still no real likelihood of a goal. Penalties is the only fair way to separate these two teams who have played out a real stalemate.

That is harsh on Switzerland! It's a really good goal as Argentina break, with Palacio finding Messi. The Barcelona man skins a player, drives forward and finds Di Maria to his left, who slots a really good finish beyond Benaglio into the bottom corner. Argentina have surely won it.

There will be three minutes of stoppage time here! Can Switzerland do it? Benaglio is up for a corner!

OFF THE POST! Oh my word! Switzerland so close to equalising. The ball is put in from the right and Dzemaili heads it against the foot of the post from a few yards out before poking the rebound wide. That was the chance.

Benaglio tries to score at one end before Argentina break and Di Maria puts it just wide of the open goal. What a finish.

BOOKING: late booking here for Garay as he brings down Shaqiri on the edge of the box. It was soft, but Garay did lunge in so he deserves to give away a free kick. Can Shaqiri do it?

Wow. What drama late in that extra-time period. Di Maria, the worst player on the pitch until that point, scores the winner in the dying minutes and they will now take on Belgium or the USA.

Thanks for joining me for this one. We'll be back soon for the final round-of-16 game, which kicks off at 9pm. From me here, though, it's goodbye.