Jonathan Jurejko
BBC Sport tennis news reporter at Wimbledon

I mean, come on! That is a ridiculously close call.

I feel like there have been so many shots over this fortnight which have led to a different opinion between the naked eye and the technology.

There is a margin of error with the electronic line-calling system of about 2.2mm.

But maybe my eyesight is simply getting worse with each advancing year...

Again Alexander Zverev reacts to a frustrating miss by crouching down. That knee must be feeling fine.

The German drives a backhand down the line for 15-15, but Jannik Sinner holds him off with a wonderful drop shot.

The world number one has played that shot to great effect so far today.

Tim Henman
Former British number one on BBC One

Zverev is feeling like these close calls are going against him. It was important he finished that game off.

Image source, PA Media

No way through again for Jannik Sinner as he searches for that potentially decisive breakthrough.

Alexander Zverev crashes in a first serve to move to game points, and resets after coming out on the wrong side of a close call to hold for a 3-2 lead.

Jonathan Jurejko
BBC Sport tennis news reporter at Wimbledon

Not a single patch of the court is still sat in sunshine.

The sun might rapidly be dipping, but the level of these two supreme players is not going south as quickly.

If Zverev forces a decider then there will have to be a break while the roof is closed and the floodlights are flicked on.

But let's not look too far ahead just yet...

Marion Bartoli
Former Wimbledon champion on BBC Radio 5 Live

Sinner jumping into the backhand with a bit of extra bodyweight, trying to find the extra edge, the extra angle, just a bit of extra everywhere if you are trying to win your second Wimbledon

Shottt! Jannik Sinner pushes Alexander Zverev out one way, and leaps up to knock a terrific backhand out of reach in the opposite direction as he battles back to 30-30.

The Italian then completes the turnaround with a clever wide serve.

14 aces for Jannik Sinner and 13 for Alexander Zverev so far.

Sinner has fired in 49 winners to Zverev's 39, and made just 24 unforced errors compared to Zverev's 38.

But, as ever in a match of this magnitude, it is the timing that is as important as anything.

Zverev smashes in an overhead for 0-30.

A superb forehand from Alexander Zverev, and signs now that he is beginning to lock in again after becoming visibly frustrated at the end of the third set.

A booming first serve down the middle moves him back in front.

David Law
Commentator on BBC Radio 5 Live

It felt like Zverev went 40-0 down in that game and just thought: 'I'm going to leather it whatever'.

Image source, Getty Images

Alexander Zverev crouches down, annoyed at himself after netting a backhand as he lined up a passing shot with Jannik Sinner rushing to the net. That allows Sinner to escape.

Alexander Zverev goes on the attack, and gets his reward!

The German drives in a forehand for a third straight point and deuce.

Jannik Sinner is looking much more dominant from the baseline now. We wondered whether Alexander Zverev could maintain his brilliant start, well now it feels like he desperately needs to rediscover those levels.

Zverev takes charge following a second serve and closes to within a point of Sinner at 40-30.

A loose backhand from Alexander Zverev gets Jannik Sinner on the board at 30-15 on the second seed's serve, but the Italian can't apply further pressure here.

Sinner nets a couple of shots and Zverev holds at the start of the fourth set, as we enter a fourth hour in this final.

Marion Bartoli
Former Wimbledon champion on BBC Radio 5 Live

The thing Sinner has done so well in this match is solving problems. And he had huge problems to solve.

Zverev was unplayable at times but he just kept knocking at the door.

Todd Woodbridge
Former Wimbledon doubles champion on BBC One

Image source, PA Media

When he rolled over on his back, Zverev looked up to Sinner and said ‘I’m OK and fine’ but it was a turning point. Once he dropped serve, he was looking up to his box asking ‘What do I do?’

Jannik Sinner is so strong mentally. The set could have gone either way. These small moments are so important.

Zverev has to come out with a positive mind. I hope he doesn’t have the attitude of ‘poor me’.

Alexander Zverev left the court following the conclusion of the third set. How is that knee? How is his mind?

The German will serve first in what is now a must-win fourth set.

Jonathan Jurejko
BBC Sport tennis news reporter at Wimbledon

The momentum has switched - and switched quickly.

Sinner looks completely in control now, with Zverev having to keep his emotions in check.

He flings his racquet on the grass after missing that break point and his mind has gone walkabout too.

Andrew Castle
BBC Sport tennis commentator on BBC One

Zverev is going to have to dig awfully deep from here. He is perfectly capable of doing it but how is that knee?

Marion Bartoli
Former Wimbledon champion on BBC Radio 5 Live

This just getting so tense. Sinner was right in front of us when he completely lost his footwork. Had one hand on the grass to pick himself up. Zverev is playing so tentatively. Then he throws his racquet on the ground, which you can't do, but he just couldn't help himself he was so angry.