Image source, Getty Images

"Tson-gaaa, clap, clap, clap (repeat)." The French crowd are fully supporting their man as he toils with his serve before doing enough to keep out his Japanese opponent.

Brief break on Court Philippe Chatrier - perhaps one, or both, players needed to nip to the gents. I know the feeling.

Anyway...they are back on the clay. Tsonga opens up the fifth and deciding set, spurred on by the supportive French crowd...

Piers Newbery
BBC Sport at Roland Garros

"Nishikori has won 14 games to eight since the scoreboard interruption, and the stats suggest he's a heavy favourite now. The Japanese player won his only previous Grand Slam meeting with Tsonga in five sets at the 2012 Australian Open, he's on a five-match winning streak in five-set matches, and a seven-match winning streak against French opposition at the Grand Slams. It's not looking great for Jo."

On we go. You had better put your dinner on hold - we're heading into a fifth set.

But it is not without plenty of graft from Nishikori, who blows a double set point at 40-15. One goes begging as he slaps a baseline return long. Nishikori then slaps his racquet in frustration. The second? That slips through his grasp too. Maybe a bit of tension creeps in as he goes looking for the winner but finds the net.

Deja vu on the next point, giving Tsonga advantage. But the 25-year-old Japanese raises his game again, forcing Tsonga wide in successive points then leaving him with no reply to a powerful deep return.

Image source, EPA

Tsonga must win three games in a row to stand any chance of taking this set and, therefore, the match. A routine service game is what he needs.

The 14th seed starts brightly, racing into a 40-0 lead. Surely this is job done? Oh no. Nishikori battles back, forcing Tsonga into a lazy backhand return that dusts the clay inside the tramlines, then plucks out a pair of forehand winners from the top drawer. Deuce.

But Tsonga, spurred on by the home fans in the fading Parisian sun, responds with a quick ace and mops up with a volley. Nishikori serves for the set...

Worth pointing out again that Nishikori's revival has been sparked by that enforced break earlier. In case you missed it, three people were injured when a piece of the scoreboard on Court Philippe Chatrier was blown off by the strong Paris winds.

At that stage, Nishikori was trailing 6-1 5-2 to Tsonga and looked to be heading towards a three-set defeat. Now, after holding his serve, he is one game away from levelling after four sets...

The Roland Garros crowd are backing their man with plenty of vocal support - and boy does he need it. Tsonga rallies to hold his serve, batting off plenty of probing questions from the fleet-footed Japanese player.

Ladies and gentlemen, I predict a fifth set. Hardly rocket science, that I know, but Kei Nishikori is oozing confidence now. The 25-year-old, wearing a trendy blue headband, is light on his feet and racing around the clay court to meet everything that Tsonga throws at him. Usually with a stinging forehand which finds the tarpaulin behind Tsonga.

Image source, AFP

An air of concern hangs over Court Philippe Chatrier. That's because the French crowd sense the momentum is turning away from their man towards his Japanese opponent in this third set.

Another blistering forehand from Nishikori is countered by some dogged Tsonga returning as the pair trade blows for 30-30. Then, at the worst possible moment, Tsonga double faults to give a gift-wrapped present to Nishikori.

And the Japanese fifth seed grabs it with both hands like a child on Christmas morning, Tsonga having no response to a swift return.

Piers Newbery
BBC Sport at Roland Garros

"Tsonga is driven to distraction as another chance to get what could be the decisive break slips by with a loose forehand. The Frenchman looks to his box and curses the swirling wind and clouds of brick-red dust.

"For a man working his way back from injury, and with a 1-4 record against his opponent, it's been a good effort from Tsonga. The finish line is tantalisingly close though."

Image source, AFP

Big chance for Tsonga! Two break points are thrown his way by Nishikori. One...goes. Two...go. Tsonga looks bemused as he lambasts the impact of the swirling wind on a rogue forehand return.

Tsonga looks to have lost focus, allowing his Japanese opponent to force deuce and then take the game. Somehow - and I'm not sure he knows how - Nishikori survives.

Tsonga is not finding his first serve - good job his second is up to scratch. The big Frenchman keeps Nishikori at arm's length with his second tosses, seeing out the game with a hold to love.

Nishikori is finding his groove after that awful start on Court Philippe Chatrier. The Japanese man, aiming to become the first player from his country to reach a French Open semi-final in 82 years, gives Tsonga the eyes with a wonderful forehand winner for the game.

And I say IF Tsonga wins because it is no longer looking like a formality. Kei Nishikori turns on the style to break Tsonga's serve and claim the third set.

If Jo-Wilfried Tsonga does come through his quarter-final then he will be facing Stan Wawrinka in the last four.

Piers Newbery watching Nishikori v Tsonga
BBC Sport at Roland Garros

"Nishikori is hanging on by his fingernails as Roland Garros reverberates with cheers from Chatrier to Lenglen, Tsonga to Federer.

"The Frenchman has his chance to get that break that would leave him serving for the match, but Nishikori comes through an epic game to stay on serve at 5-4 in the third.

"Meanwhile, during the changeover, the cheers from Lenglen fill the air. Drama all over the place this afternoon."

Image source, AFP

Federer staves off the first match point. But not the second! Wawrinka smells blood and moves into the net for the kill, crashing a volley into the left corner as Federer gives up the chase on the opposite side of the clay.

Stan Wawrinka through to the French Open semi-finals at the expense of his Swiss rival Roger Federer.

Federer is NOT happy. Wawrinka is unruffled. He holds serve to lead 5-3 in the tie-break as Federer glares across the net. Three blasts from Wawrinka gives him another winner - and three match points....

Federer serves and volleys a winner at the net to level. Wawrinka forehand goes long. Or does it? The umpire gives Wawrinka the point - Federer questions the call. It is given - the first mini-break in the decider.

Wawrinka keeps his nerve with a forehand winner followed by a backhand.