Jonathan Jurejko
BBC Sport at Roland Garros

Blimey! Carlos Alcaraz doesn't know how quick he is in terms of the clock, but he knows - to quote him from an earlier news conference - he is "fast".

We see that for ourselves on Chatrier when he tears across the red dirt to reach that drop shot from Zverev.

Someone call the Spanish 4x100m relay team.

Slim pickings for Alcaraz on the Zverev serve once again. A couple of hefty forehand winners, either side of an ace, take the German clear and immediately dishearten his opponent.

A comfortable hold. Superb serving from the third seed.

Naomi Broady
British player on BBC Radio 5 Live Sports Extra

Frustrations building and starting to bubble over for Alcaraz. He's just unable to find his level at the moment.

Zverev is not having to do much to get through these games. He's only having to play one of two points in a game to get it.

Nicely done. Alcaraz gets the better of Zverev at the net and you can see what that means to him, waving his fists towards his team as he takes a seat.

It's not gone to plan so far, but he's hanging in there.

A miss from Alcaraz brings Zverev into play, and a double fault makes it 30-30.

Another brilliant drop shot gets him out of trouble for now. What a shot that is. Zverev anticipated that one and still couldn't reach it.

Naomi Cavaday
BBC Sport tennis commentator

Zverev has so much height and he has so many levers, it is so hard to return that serve - when it is on.

Ah, Alcaraz lets Zverev off the hook with an overly enthusiastic forehand.

The groans echo around Court Philippe Chatrier, as the Spaniard again has a word with himself at the back of the court.

Boom, a huge forehand from Zverev seals the hold. A big hold too.

A double fault from Alexander Zverev.

Alcaraz can sense his opportunity here, the Spaniard darting across the court to whip an angled forehand back over and reach break point!

Not so fast!

Alcaraz manages to get on top of a rally after digging out a return on the run, popping a drop shot over which leaves Zverev stranded. We go to deuce...

A serve and volley from Alexander Zverev doesn't quite go to plan, but he quickly shakes off that miss with an ace.

Yep, it's looking like more of the same on the German's serve as Alcaraz drops a backhand into the net for 40-15.

Naomi Cavaday
BBC Sport tennis commentator

Every sort of gamestyle you could possibly play - you tend to see in an Alcaraz match - he likes to keep his opponents guessing.

Jonathan Jurejko
BBC Sport at Roland Garros

Since facing that break point in the second game of the match, Zverev has looked extremely comfortable on his serve.

Alcaraz has only won two receiving points since.

A fine reply from Alcaraz. A comfortable hold to love is just what the doctor ordered, with Zverev still looking relatively untroubled so far.

Jonathan Jurejko
BBC Sport at Roland Garros

Has anyone made the 'Escape from Alcaraz' gag yet? No? About time we did.

The Spaniard had to wriggle out of a tighter situation than Clint Eastwood did in the 1979 classic film (that's Escape from Alcatraz if this reference is lost on you) during his second-round match against fellow Spaniard Albert Ramos-Vinolas.

Alcaraz survived a match point before making his dash for the third round.

And, quite remarkably, Zverev had to do the same in his second match against Sebastian Baez.

Alcaraz just about prevents himself from launching a ball out of the arena as his frustration against Zverev's serve continues to grow. It's a swift love hold for the third seed.

Flashes of brilliance interspersed with potentially costly misses from Alcaraz. A stunning get at the net takes him to game point but another miss gives Zverev hope.

Not to be for the German here. Alcaraz gets the start he needed.

Response. A couple of devastating forehands put Alcaraz in charge on serve.

Ah, but there's another of those cheap, unforced errors which plagued his first set.

Image source, Getty Images

Naomi Broady
British player on BBC Radio 5 Live Sports Extra

I feel a bit confused. I was bigging Alcaraz up, but he's really struggled to make the court. I know it's only the first set, but I'm intrigued to see how Alcaraz handles this adversity.

He's trying to be super aggressive because that's how he plays but when you have to dial that back, it's tough to win ugly.

It'll be Carlos Alcaraz who gets us back under way in set two.

Can the 19-year-old respond here after a sluggish start to this quarter-final?

Jonathan Jurejko
BBC Sport at Roland Garros

A slightly subdued atmosphere on Chatrier, where the Spanish players - notably Nadal, of course - always receive vociferous backing.

Lots of applause and respect for Zverev, though, as he wraps up the opening set.

Alcaraz is nowhere near top gear yet, having made 16 unforced errors.

That's double the amount of winners he has landed.

Image source, Getty Images