Here's some context for you. Stan Wawrinka has come back to win from two-sets behind on six occasions. However, he has never done that against Roger Federer. And he has never beaten Fed on a hard court. Oh, and he is 18-3 down in their head-to-head remember. Make of that what you will...

Back on court, Wawrinka huffs and puffs in his service game, eventually blowing Federer over.

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When Federer moves into a 30-0 lead, Stan deciding to start swinging. He slashes at a short ball with a forehand that goes fractionally long, then puts too much beef into a backhand. All square.

Wawrinka is back in the arena after that medical timeout - he's getting this third set underway. Wawrinka now has some strapping below his left kneecap for a bit of extra support but Federer shows no mercy to take a 30-15 lead with a high volley. 

A couple of big serves lay the platform for the hold though. Phew, sighs Stan.

Pat Cash
Former Wimbledon champion on BBC Radio 5 live sports extra

Not too many people have come back from two sets down against Federer. Tsonga did it at Wimbledon but it doesn't happen very often because it's so hard to get into a Federer service game.

Stan won't be fightened of getting stuck in but he's making a couple of unforced errors and is getting pulled around by Federer. Roger is so clever the way he slices and dices the ball, but Stan has to attack the Federer backhand.

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Stan covers his head in white towel. Time for reflection at the changeover. Time for the trainer... Wawrinka wanders off inside for a minute or two as he calls an injury time-out, Roger sticks on his tracky top to keep warm.

Wow, just wow. Roger Federer has simply blown Stan Wawrinka off the court in this second set. Nobody - well, almost nobody - comes back from two sets down against Federer. But that's what Wawrinka is going to have to do if he wants to reach his second successive Slam final.

It is a routine hold for Federer, who moves into the net and volleys for a 30-0 lead, a backhand winner followed by a big forehand down the line which leaves Wawrinka rooted.

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That more like it. Wawrinka races into a 40-0 lead, but can't seal a morale-boosting hold as a tricky cross-court half-volley drops wide.

And then he punches a net volley long for 40-30. Squeaking? Nope, he regains composure to force Fed into a mistake.

If Fed is winning this set then he's doing it on his own terms...

Pat Cash
Former Wimbledon champion on BBC Radio 5 live sports extra

The match is being played on Federer's terms, as they so often are. Djokovic and Nadal have managed to push him back behind the baseline but you've got to be extremely fast to do that, and it's a big ask to do it on a fast hard court. 

The big swings of Stan require a little bit more pace but Federer does not give him the time.

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Stan's head is in the washing machine. And Federer is providing the electricity which is putting it a spin. Federer knows he has got to his fellow Swiss, ramping up the pressure with his serve as Wawrinka wilts. Fed one game away from a 2-0 set advantage...

Meltdown. Federer breaks Wawrinka's serve, Stan breaks his racquet. Fed's got to his head.

Stan overcooks a simple forehand with the court gaping - setting up two break points for Federer.

Stan lashes a ball in his pocket at the speed gun. Keep your cool Stan... A forehand down the line - similar to the one he missed - saves one. But not the second.

Another backhand error gives Federer the break. And it is goodnight for his racquet. That gets ploughed into the blue acrylic, then gets snapped in two over his knee. Ouch.

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Wawrinka barely laying a glove on the Federer serve. Two quick points put the game within reach of the 17th seed, Stan's hound-dog expression telling you he is almost writing it off. He does get on board thanks to a rogue Fed backhand - remember the time and place -  but that is as good as it gets.

I've got to admit - there is not too much drama so far in this second set. More Doctors than EastEnders. Stan Wawrinka moves into a commanding 40-0 lead with a blistering ace, a slight blip helping Roger battle back to 40-30. But there's no cliffhanger ending as Wawrinka wraps up the game at the next attempt.

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Who's going to blink first? Not Federer. Yet, at least. The Federer serve is almost as good as it has ever been. Even under intense pressure from Wawrinka. A forehand volley sees Federer home again.

Comfortable service games have been rare. Both men have been pushed all the way - but Wawrinka's opening throw of the second set is almost as comfortable as it has been.

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Pat Cash
Former Wimbledon champion on BBC Radio 5 live sports extra

Bjorn Borg had the rock star looks, and the screaming girls, but everybody loves Federer and wants to see him play well.

Don't blow that momentum now Rog. He doesn't. Federer kicks off the second set and begins with a comfortable(ish) hold. Stan briefly threatens at 40-30 before Federer brings out an ace at the crucial time.

BBC Radio 5 live

Big words from a big name. 

Andy Roddick, winner of the 2003 US Open, says an Australian Open final between Roger Federer and Rafa Nadal could be ‘the most important match in Grand Slam history.’

“The historical context of what we might see, it’s definitely the most important match in Australian Open history if it gets there, possibly in Grand Slam history,” said Roddick.

Listen to the full 5 live interview with A-Rod or watch, external a clip on their Facebook page.

So it is still on then. Federer v Nadal. Can it? Will it?

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Pat Cash
Former Wimbledon champion on BBC Radio 5 live sports extra

Wawrinka was under pressure and made two unforced errors - that's the bottom line.

Roger ramps up the pressure - and Stan buckles! Breakthrough for Federer.

Wawrinka never looks like very happy. And he is almost growling as Federer moves within a point of the first set. The Rod Laver Arena crowd are not shy in letting him know they are pro-Federer.

Wawrinka serves...Fed bats one back...Stan targets his backhand...but he finds the tape

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