Charlotte Coates
BBC Sport at Wimbledon

Plenty of “come on, Ben” cries from the crowd. I think they can sense this could be over rather quickly at this rate.

These fans want a contest.

Todd Woodbridge
Former Wimbledon doubles champion on BBC Two

Shelton has to work on some better structure of points. There are some random tactics.

At the moment he is being completely shut down by Sinner.

You have to wonder how much the first week of Wimbledon has taken out of Ben Shelton.

He may only be 21 and feel he has endless energy but playing three five-set matches and being on court on all but one day surely has to catch up eventually.

It doesn't help that he's up against the formidable Jannik Sinner.

The Italian gets another break and it's starting to look ominous.

Stunning from Carlos Alcaraz!

With Ugo Humbert racing to the net after a fine approach shot, Alcaraz whips a perfect passing shot down the line.

The ball swerves in late to get inside the line and Humbert can only applaud.

Image source, Reuters

Charlotte Coates
BBC Sport at Wimbledon

Great stuff, just taken my seat to watch Jannik Sinner expertly serve for the first set.

I’m sat directly across from six men wearing green t-shirts that spell out ‘Jannik’.

Todd Woodbridge
Former Wimbledon doubles champion on BBC Two

You need to be disciplined on what you work on. Shelton needs to work on some shoulder rotation, get racquet strings on the ball and get it back into play.

Image source, Getty Images

Jannik Sinner with some fine serve and volley to take a 30-0 lead.

He will have three attempts at set point as Ben Shelton's backhand goes long.

The American fails to return the following serve and that's the set in just 29 minutes.

It's not quite the 21 minutes it took Sinner to wrap up the opening set against Miomir Kecmanovic in round three but still very impressive!

Tim Henman
Former British number one on BBC TV

Carlos Alcaraz was the better player in the first set but in the next three, Ugo Humbert really has matched him.

Gasps from the crowd and a shake of the head from Carlos Alcaraz as he puts an attempted passing shot into the net.

That would have made it 15-30 and ramped up the pressure on his opponent.

Instead, Ugo Humbert closes it out and is now just a game away from forcing a fifth set.

Todd Woodbridge
Former Wimbledon doubles champion on BBC Two

Shelton needs to keep points as short as possible and get as many free points on serve as he can.

Todd Woodbridge
Former Wimbledon doubles champion on BBC Two

Sinner seems to have so much time on the ball, getting set beautifully and his balance is just significantly better than that of Ben Shelton at the moment.

Jannik Sinner reads another of Ben Shelton's drop shots but then fails to convert at the net.

There's nothing to criticise about his serve, though, as he gets to 30-30 with a 134mph effort right on the T.

Sinner gets another attempt to break and he takes it.

The Italian will serve for the first set.

Cheers from the fans on Centre Court as Carlos Alcaraz fights his way to a hold from 0-40 down.

An ace got him to advantage and another first serve was swatted back into the net by Ugo Humbert.

We're still on serve in this fourth set but that's a missed opportunity for the Frenchman.

Image source, Getty Images

Oh dear. The rain is back and the covers are back on.

On, off, on, off. Will we get more than an hour of consecutive play at all today?

As things stand we're not expecting any further play before 16:30 BST.

Image source, Getty Images

Charlotte Coates
BBC Sport at Wimbledon

Huge demand to get on Court One in the press seats.

I’ve been here a good few times but I’ve never seen it this busy. It’s no surprise given the quality out on court.

Jannik Sinner looks like he can't put a foot wrong on serve as he moves into a 30-0 lead - that's 10 unanswered points in a row.

Ah, I spoke too soon. All good things have to come to an end as Sinner fires into the net 30-15.

But it's business as usual after that as Sinner takes the next two points.

Three break points... all saved by Carlos Alcaraz.

He's having to get his first serve in and he does so to great effect.

Tim Henman
Former British number one on BBC TV

It feels like Ugo Humbert is just swinging for the fences and everything is going in.

Goodness me. Carlos Alcaraz is down 0-40 and on the brink of being broken for the sixth time in seven service games.

Todd Woodbridge
Former Wimbledon doubles champion on BBC Two

Keep an eye of the balance of both players.

Sinner has the ability to get his bodyweight even or down to the court.

Sinner is moving the best he's ever moved on grass. Shelton was flailing on the grass.