What a sickener for Tsonga! After trailing 40-0, Wawrinka completes a remarkable turnaround, after initially wasting a first break point, to nab the first steal of the match. The decibel meter inside Court Philippe Chatrier has dropped a little already...

Facing a Tsonga serve would be up there with waiting for a Curtly Ambrose delivery in my list of least fancied sporting situations.

The Frenchman blasts down a few bombs, all whizzing down around the 210km/hr mark, to lead 40-0. Job done one would think. But Stan has other ideas!

The Swiss, so powerful and precise against Federer in the last round, finds his groove to draw back level with a delicious backhand cross-court winner. Deuce....

Image source, Reuters

Wawrinka will be aiming to quieten this Chatrier crowd early doors and the best way to do that is by giving Tsonga nothing on his serve. The Swiss man does just that - holding to love in a routine service game. Much easier than his first effort...

Here we go - big-serving Tsonga's turn to blast down some questions. Wawrinka's sliced backhand return partly answers for 15-15, before Tsonga ups the ante. The Frenchman's first ace of the match - and one suspects there may be a few more - wraps up the hold.

Image source, AP

We are open for your predictions, wisdom and witticisms.

Who do you think will emerge from today's hostilities as the two finalists? And who do you want to win the two semi-finals?

They may be very different answers.

Let us know via #bbctennis, external on Twitter and 81111 on text.

First break point - saved by Wawrinka. Second break point - wasted by Tsonga. The Frenchman ungainly holds up his racquet to prod an uncomfortable-looking backhand volley towards Wawrinka territory, only to find the tape. Tsonga wins another break point to whip the Paris crowd into a frenzy, but Wawrinka is made of stern stuff. The Swiss eighth seed roars back to hold under extreme pressure.

Image source, AP

Huge cheer from the home crowd as Tsonga wallops a forehand past Wawrinka to level at 15-15. Another deep Tsonga forehand - dusting the right angle between baseline and tramline - is palmed into the net by Wawrinka for 30-15, then a carbon copy point hands Tsonga two break points in the first game...

Miles Maclagan
Former coach to Andy Murray and Laura Robson on BBC Radio 5 live sports extra

"I am leaning towards Wawrinka. The tennis he has played when he has been on form has been pretty much unstoppable. The heat and the crowd favour Tsonga, but I think that Wawrinka will have just enough."

Click on the audio icon above for live 5 live sports extra commentary.

Image source, AP

Stan Wawrinka waves as he is introduced to the Chatrier crowd, gulping down a mouthful of something energy-boosting. A white-cap-wearing Tsonga sits down next to him, takes a deep breath, then climbs back to his feet. Wawrinka to serve first....

The Paris sky is bluer than the Indian Ocean. And the Roland Garros clay is redder than a sweet, ripe tomato from my grandad's allotment. The sun is shining, the stage is set....

Piers Newbery
BBC Sport at Roland Garros

"It's nearly half full as the players knock up, which is good going in these parts. This must be big. "Allez Joe!" translates directly as "Come on Tim!", with the locals undergoing their own annual purgatory as Tsonga attempts to end the wait for a men's champion.

"Admittedly, they have had to wait only a paltry 32 years and counting, compared to the UK's 77-year hiatus between male Wimbledon winners, but it's starting to drag here too.

"If Tsonga can get off to a fast start then the full force of Chatrier will get behind him. The alternative is the nightmare of two years ago, when Big Jo was rolled over by David Ferrer in an atmosphere as flat as a crepe."

Image source, AP

You know it is scorchio when Jo-Wilfried Tsonga decides to ditch the all-black attire in favour of cooler, light-deflecting white t-shirt. Both players wear beaming smiles as they shake hands, contest the toss and then bring out the cheesy grins for a pre-match photo. Ahhh, nice.

Almost show-time! Court Philippe Chatrier rises to its feet to welcome their gladiator into the arena. Jo-Wilfried Tsonga, who looks almost embarrassed by all the attention, leaves the locker room first, just ahead of Stan Wawrinka. The Swiss receives a, shall we say, more muted welcome.

Apparently a weather warning has been issued at Roland Garros - with the possibility that everyone might be moved off Court Philippe Chatrier later on if the expected high winds materialise. Let's hope that doesn't happen...

Pat Cash
1987 Wimbledon champion

"I think Wawrinka has a real chance for this title. He's so full of confidence, beating his hero Roger Federer in straight sets in the quarter-finals.

"Tsonga hasn't got a lot of 'runs on the board' this season, so I'm wondering if his legs will finally give out and the [need for] concentration will just get a bit too much for him, with the [home] fans and everything."

Stan Wawrinka managed to get plenty of the Roland Garros crowd on his side and he bished and boshed his way past Swiss compatriot - and huge Paris favourite - Roger Federer in the last eight on Wednesday.

But don't expect much support today, Stan. Instead he will be expecting a partisan atmosphere on Court Philippe Chatrier as the French fans cheer on their man Jo-Wilfried Tsonga.

The 30-year-old is contesting his second French Open semi-final - and sixth Grand Slam semi overall. He will become the home nation's first men's singles finalist since Henri Leconte in 1988 if he manages to see off Wawrinka.

Court Philippe Chatrier is filling up nicely, the fans trooping into their sun-soaked seats. Hope they are all armed with sunscreen and a floppy hat. We are about 10 minutes until lift off....

Image source, Getty Images

First round: beat Christian Lindell 6-1 6-2 6-2

Second round: Dudi Sela 6-4 6-1 6-1

Third round: beat Pablo Andujar 7-6 (7-3) 6-4 6-3

Fourth round: beat fourth seed Tomas Berdych 6-3 6-2 6-7 (5-7) 6-3

Quarter-final: beat fifth seed Kei Nishikori 6-1 6-4 4-6 3-6 6-3

Image source, Reuters

First round: beat Marsel Ilhan 6-3 6-2 6-3

Second round: beat Dusan Lajovic 6-3 6-4 5-7 6-3

Third round: beat Steve Johnson 6-4 6-3 6-2

Fourth round: 12th seed Gilles Simon 6-1 6-4 6-2

Quarter-final: beat second seed Roger Federer 6-4 6-3 7-6 (7-4)

Piers Newbery
BBC Sport at Roland Garros

Image source, Reuters

"It is, as predicted, a Parisian scorcher. Djokovic has just completed his morning hit on the Chatrier stadium and Murray is now belting backhands under the watchful eye of coach Amelie Mauresmo.

"The temperature is 28C and climbing steadily, with the latest word that any storms might not arrive until the evening."