Marco Cecchinato takes the opening point of the eighth game, but sends a return well wide with his next shot. 15-15.

We have already seen one match today severely affected by an injured competitor and we may well be seeing another one now. At the end of that last game Novak Djokovic got the physio out to look at a shoulder / neck injury.

One to monitor, but at the moment we continue with Djokovic serving to save the set.

A fist pump from the Italian, as he holds his serve to move one game away from taking the opening set of this quarter-final.

We didn't see this one coming.

At the moment Novak Djokovic, who won at Roland Garros two years ago, is 4-2 down in the opening set, with work to do for the Serb.

Thanks Alex. We already know that Dominic Thiem will be playing in the French Open semi-finals, but who will be the man standing at the opposite end of the court?

I'll pass the French Open baton on to my colleague Michael Emons to pick up that Djokovic-Cecchinato clash...

It's got the makings of a cracker.

So Dominic Thiem will face now the winner of the quarter-final between Novak Djokovic and Marco Cecchinato.

We're going to pick that up in a second, with unseeded Italian Cecchinato currently a break to the good and leading 4-1 over on Court Suzanne Lenglen.

An upset on the cards?

And here is Dominic Thiem: "It was very tough for him today. He's one of the fittest guys on tour but even for him it's tough to play three five-setters in a row.

"I hope we have many more encounters this late in a Grand Slam and maybe even later, it will be even nicer for everyone.

"I love it so much here and the third time in a semi-final sounds amazing. When I was a junior I never expected this.

"It's time for me and I will give everything to make one more step this year."

Leon Smith
GB Davis Cup captain on BBC Radio 5 live sports extra

A strange match to comment on. Zverev is a popular figure, he's had an incredible year but it wasn't really a match. Zverev looked very tired and jaded and struggled with his hamstring but Thiem has won in one hour and 50 minutes and will be fresh in the semi-finals.

Well, Zverev looked a broken man from early on in the second set. But Thiem played a great match.

It's a third French Open semi-final in a row for the Austrian.

Super passing winner.

A third match point for Thiem.

This is agonising. Zverev punches wide. Match point Thiem for the second time.

But Zverev fights back again!

Deuce.

Zverev refuses to give up. Backhand winner that slides away from Thiem.

Thundering backhand from Alexander Zverev. But it's called out by the line judge after a quick check.

Match point.

A quick exchange of points and we're back to deuce, before Thiem punches a forehand long from wide out.

Advantage Zverev, only for the German to miscue. Back to deuce then.

Jonathan Jurejko
BBC Sport at Roland Garros

Image source, Reuters

Zverev is looking a bit like a heavyweight boxer out there.

Not in stature, obviously (although he is 6ft 6in), more that the skinny German is refusing to chuck in the towel until he is KO'd.

And every now and again he is digging deep into those diminishing energy reserves to land one on Thiem.

Dominic Thiem is still full of energy, wheeling in to meet another Zverev drop shot and win the point.

Deuce.

Zverev goes for the net again, but a scuttling Thiem picks it up over the German and Zverev punches long as he backpedals.

40-30.

A swerving Dominic Thiem forehand on the run can only find the tramlines. That's 15-15.

Alexander Zverev follows up with a cute drop shot volley at the net.

30-15.