Here we go. Stan takes a good gulp of ice-cool water, making Federer wait a couple of moments. Roger to get the ball rolling...

* denotes next server

Image source, Getty Images

Russell Fuller
BBC tennis correspondent on Radio 5 live sports extra

If 35-year-old Roger Federer wins he will be the oldest man to reach a Grand Slam final since Ken Rosewell who was at 39 in the US Open final of 1974.

The Rog-naissance has been extraordinary. Come on, hands up. Who thought he would go so deep in Melbourne? Hmmm, I'm not sure I believe you.

Federer's extraordinary run - seeing off the likes of Tomas Berdych and Kei Nishikori - sees him become the oldest Slam semi-finalist since Jimmy Connors at US Open in 1991. And the oldest Australian Open semi-finalist since Arthur Ashe in 1978.

Russell Fuller
BBC tennis correspondent on Radio 5 live sports extra

I have been amazed by Roger Federer, I think it will be very close but I think I favour Wawrinka to win, but I don't say that with confidence.

The longer the match goes on you'd think Wawrinka as the younger man, but Federer is incredibly fit and has had six months off recovering from his knee injury so is fresh.

Image source, Reuters

Rowland: I've got a big spanner for Stan.

"Fasten your seatbelts!" whoops the man behind the mic in the Rod Laver Arena. He's expecting a rollercoaster ride.

Shrieks akin to those heard at a One Direction gig greet the arrival of the two players. Almost show-time...

Getting hung up on those numbers won't do Stan's frame of mind any good. Luckily the three-time Grand Slam winner isn't focusing on them.

"Against Roger, it's always special because he's so good. He's the best player of all time," says Wawrinka, who has beaten his long-time friend at a Slam - in 2015 French Open quarter-final.

"He has an answer for everything. But I managed to beat him in a Grand Slam, so we'll see.

"It's great to see him back at that level. Hopefully I can manage to play a great match."

Ah, a timely reminder Russell. Thanks. Their head-to-head record. Look away now Stan...

Federer has been totally and utterly dominant against his old friend. Roger has won 18 of their 21 previous meetings, including all 13 matches on hard courts.

Russell Fuller
BBC tennis correspondent on Radio 5 live sports extra

Wawrinka has won everywhere but Wimbledon, is playing really good tennis but on the other side of the net is Federer, his good friend and senior Swiss partner, who has an overwhelmingly favourable record against him.

So who are you backing? Will Roger's remarkable run continue? Or will Stan stick a spanner in the works?

Let us know by tweeting #bbctennis or texting 81111. Don't leave me hanging.

BBC Radio 5 live sports extra

Hello! And welcome to the business end of the Australian Open. Tennis used to be a young person's game. Not any more.

The Williams sisters, Mirjana Lucic-Baroni, Rafael Nadal and, of course, Roger Federer and Stan Wawrinka are all proving that turning 30 is no barrier to Slam success.

But you've got to feel slightly sorry for Stan. The whole world is seemingly licking their lips about the prospect of a Federer v Nadal final.

And a reminder that live commentary is under way on Radio 5 live sports extra, assessing the all-Williams sisters women's final and Federer v Wawrinka's semi-final. Click on the link at the top of the page to hear it.

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If there's one thing that is going to test Swiss impartiality then it's name is Roger Federer. The Maestro usually has unwavering support back home - and across the world - when he floats and glides around a tennis court.

But what about when he is playing Stan Wawrinka? Split loyalties? Maybe back in Switzerland. Probably not in Melbourne.

Image source, Getty Images

Switzerland is well-known for being a 'neutral' country. The landlocked Central European nation has long maintained its stance of neutrality, refusing to become involved in conflict as a means of protecting its national security from outside interference.

It is the oldest neutral country in the world, having not fought a foreign war since 1815. Which means the good Swiss folk know all about having to stay centrally positioned in the middle of a heated battle.

Ideal for a nation which has two of the world's best tennis stars scrapping for a place in the Australian Open final...

So will it be Serena moving ahead of Steffi Graf with a record 23rd Open-era Grand Slam title?

Or will Venus become the oldest female Grand Slam champion in the Open era?

History is going to be made one way or the other...

We will be back with live text coverage of Roger Federer against Stan Wawrinka at around 08:20 GMT.

One for the cameras...

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Serena WIlliams: "Mirjana is an inspiration and deserves all the credit today. To get so far after all she has been through inspires me and I wanted to give her all the congratulations.

"It is great to see her out here. I was rooting for her through the whole tournament.

"The serve was a little better today, I want it to be a little better, I knew it needed to be good because Mirjana is a great returner.

"I am really proud of Venus, she is a total inspiration and a big sister. I am really happy for her and to be in the final together is a dream for us really.

"She is my toughest opponent, no-one has ever beaten me as much as Venues. I feel no matter what that we have both won after all we have been through. I know a Williams is going to win this tournament."

Lucic-Baroni is chasing hard, but those Serena groundstrokes are not getting any closer.

Two chunky netcords break Williams' way on the final rally before she boshes away down the short side for a winner. When even Lady Luck is backing the favourites, Lucic-Baroni might decide this job is beyond her.

Mirjana Lucic-Baroni kicks out at the stray ball in anger as she double-faults to a double-break down.

The first semi-final was a proper tussle, this public dissection is taking place in an atmosphere akin to a morgue.

A swishing forehand, a dead-eyed stare down the other end -Serena Williams is taking care of business as she speeds towards a final sister act.