Another shank by Jannik Sinner and he can't find the court on Alexander Zverev's next serve.

The break point comes and goes. An important hold for the German.

Image source, PA Media

I'm not sure what happened to Jannik Sinner there. A complete mis-hit by the Italian nearly sends the ball into the crowd.

Russell Fuller
BBC tennis correspondent on BBC Radio 5 Live

This is the pressure point of the first set. A slip here from Zverev and Sinner is serving for the set.

Oooh. The first double fault of the match and it's an untimely one from Alexander Zverev as it hands Jannik Sinner the first break point.

Jonathan Jurejko
BBC Sport tennis news reporter at Wimbledon

There has been more ball-bashing than deft touches so far, but that feather-like flick from Sinner was a reminder that he really does have it all in the locker.

That's got the crowd purring - and could be a pivotal moment.

An ace straight down the line brings up game point for Alexander Zverev, but the German loses the battle of the drop shot as Jannik Sinner slides in and sends an angled one across the net.

A miss by Zverev and we go to deuce.

As soon as Jannik Sinner sits down for the change over, he wraps an ice towel around his neck.

It's around 29C out on Centre Court at the moment and we know that Sinner has struggled in the heat before - most noticeably in his shock second-round French Open defeat last month.

It will be interesting to see how he fares physically today if this match goes the distance.

Todd Woodbridge
Former Wimbledon doubles champion on BBC One

Image source, Getty Images

It is certainly is a fantastic serve from Sinner. His accuracy and improvement can be seen over the last three years.

When you are this close you can also see the consistency of the ball toss, when he places the ball, it doesn’t spin, you can see the brand of the ball.

Jannik Sinner shakes his racquet as Alexander Zverev finds the fence. Another service game safely navigated.

Alexander Zverev thought he had squeezed a pass into the corner, but it's called out, much to the 29-year-old's displeasure.

Jannik Sinner replies with a forehand winner down the line and an ace, but he's unable to wrap up a love hold after swatting the ball wide and then long. 40-30.

Pat Cash
Former Wimbledon champion on BBC Radio 5 Live

No great surprises yet this match.

A positive start for Zverev, but my concern is him going for aggressive shots when defensive shots would work, but the balance has been pretty good so far.

Image source, PA Media

Jannik Sinner plants one return into the net and then fires one long. He can't even get a racquet to Alexander Zverev's next serve.

A very comfortable love hold for the German.

Six games down, no break points.

Jannik Sinner mixes up his serves, with one out wide and one down the T. Alexander Zverev can't do much with either.

The defending champion nudges ahead again.

Jonathan Jurejko
BBC Sport tennis news reporter at Wimbledon

Zverev's yell echoes around Centre Court when he pushes a forehand wide at 15-30.

He knows that was a decent chance to get a look at the break, but was a bit too keen and is annoyed that he did not execute it properly.

Jannik Sinner claws one point back with an ace before Alexander Zverev flings a forehand into the tramlines and lets out a frustrated roar. 30-30.

Andre Agassi
Former Wimbledon champion on BBC One

We are only four games in but if you had to pick someone who is hitting the ball cleaner, I’m liking the way Zverev has started this match.

Image source, PA Media

A weak forehand into the net puts Jannik Sinner on the backfoot and Alexander Zverev capitalises by whacking the ball down the line with some serious pace to open up a half chance. 0-30.

Tim Henman
Former British number one on BBC One

It is the ball striking and the athletic ability [that is impressive], they’re so agile in and out of those corners. You get a good strike in and it comes back within inches of the line.

Marion Bartoli
Former Wimbledon champion on BBC Radio 5 Live

Zverev has improved his serve so much this year. We have seen him practicing for hours and hours in Aorangi Park, but it is paying off.

Alexander Zverev pummels a forehand winner beyond Jannik Sinner's reach to wriggle free and hold serve.