Oh, a fall on the baseline from Sinner after Alcaraz floats the drop shot in and that hands the Spaniard set point.

The top seed quickly gets up and looks fine.

Tim Henman
Former British number one on BBC One

Sinner is targeting the Alcaraz forehand. However, if you drop it short on Alcaraz's forehand, you could be doing some running.

This is corner to corner, the ball striking and the reactions.

Alcaraz was searching for that break back and this was not what Sinner was looking for, to serve to stay in this first set.

Having taken that first break Sinner is now serving to stay in the set.

He struggles to find a first serve but another tense rally from the baseline sees Alcaraz fire wide. 15-15.

Image source, Getty Images

Jonathan Jurejko
BBC Sport senior tennis reporter at Wimbledon

Woof! The chuckles of astonishment tell you how good that Alcaraz serve which wrapped up the hold was.

As did the puff of white chalk which sprung up and the 140mph clocked up by the speed gun.

It feels like another subtle momentum shift. Will it be enough for Alcaraz to clinch the set?

Another devastating serve that Sinner returns well but Alcaraz just plonks his forehand into the empty space.

A 140mph ace that kisses the line wraps up the hold.

A collective groan as Alcaraz makes the first double fault of the match.

A big second serve puts him back on level terms at 30-30.

Image source, Getty Images

Alcaraz breaks back as Sinner dumps into the net.

Goodness me. Some of the shots in that game.

We're cooking now, folks.

Sinner goes long. Two break back points for the defending champ.

A big roar from Alcaraz as he turns up the heat and brings up an opportunity to work a break point at 15-30.

Jonathan Jurejko
BBC Sport senior tennis reporter at Wimbledon

Breaking Sinner's serve hasn't been easy for his opponents this fortnight, but Alcaraz must find a way if he isn't going to lose this opening set.

Sinner has faced 17 break points and saved 13 of them. Only Grigor Dimitrov in the fourth round and Novak Djokovic in the semi-finals pinched his serve.

In comparison, Alcaraz has faced 49 break points.

Oh my goodness.

What a shot. Wow wow wow.

A brilliant rally ends with an Alcaraz backhand volley at the net with a ridiculous amount of spin on it.

He did that earlier on the practice courts but we wondered whether he'd have the audacity to try and attempt it here.

Of course, he does.

Andrew Castle
BBC Sport tennis commentator on BBC One

Image source, Getty Images

The world number one's movement is phenomenal. He is exploding on the ball. He may look slight, but in real life, powerful.

The way they are both crunching the ball at the moment, it's as if the future has arrived really quickly after a generation who produced some amazing finals.

Alcaraz wraps up the hold when he drags Sinner into the net then zips one past him.

Sinner is so wrapped up in this match that he starts to head back to the baseline. Not yet Jannik, have a seat first.

The sun has gone in on Centre Court and it's offering these fans a moment of respite from that oppressive heat.

Sinner hugely on the defence as he's left diving for a big forehand for 40-15.

Jonathan Jurejko
BBC Sport senior tennis reporter at Wimbledon

Sorry Alcaraz fans - commentator's curse struck.

The Spaniard edgily knocking a backhand into the net after Sinner returned his first serve at deuce proved pivotal.

That came seconds after he slipped stretching for a return.

Clubbing a forehand long on break point after being pushed back behind the baseline didn't help, either.

Too good Sinner.

He sends Alcaraz one way with the drop shot then the other and even the Spaniard, who moves so incredibly well, can't get to it.

An ace consolidates the break for Sinner.

Image source, PA Media

Sinner follows that break of serve with some solid serving but a couple of wayward returns from the Italian put Alcaraz right back in this game at 30-30.

Tim Henman
Former British number one on BBC One

Sinner was really putting the pressure on in that last game and was anticipating the shots from the Spaniard.

He stuck at it to get four points in a row, despite the backhand from Alcaraz, and gets the break.

A wild forehand from Alcaraz and the first break goes to top seed Sinner.

Aggressive game from the Italian and it pays off.

Jonathan Jurejko
BBC Sport senior tennis reporter at Wimbledon

Image source, Getty Images

Carlos Alcaraz has made slightly slow starts in his service games over the past fortnight - well, by his sky-high standards.

You felt he couldn't afford to do that against Sinner. He hasn't yet.

A healthy first-serve percentage from both men - each finding pace and precision - has contributed heavily to this even start.