Greg Rusedski
Former British number one on BBC Radio 5 Live and BBC Sounds

The Bulgarian just has all the answers at the moment, doesn't he?

He has had this expectation on him for such a long time. He was known as 'Baby Fed' [Federer] when he first came through and he didn't like it. He couldn't handle the pressure and expectation, so it's good to see him enjoying his tennis again.

If he plays with freedom, he can beat anybody on the day.

Clara Tauson was dominating on the Iga Swiatek serve early in the match - she can't get near her now.

Another hold to love for Swiatek. Still on serve in this second set but Tauson already feels up against it.

Image source, Getty Images

And hold serve, he does.

A brilliant backhand down the line finds the chalk at the back of the court. Just.

On comes the trainer so we'll have a short delay while he assesses Jannik Sinner's elbow. It's a medical time-out.

Tim Henman
Former British number one on BBC Two

Dimitrov has been very successful moving forward. He sometimes he gets himself caught in volleys when he is a little too far from the baseline.

Sinner has to hold serve here, irrespective of how sore his elbow is.

Image source, PA Media

Andrew Cotter
Commentator on BBC TV

All is not entirely well with Sinner. He is pointing to his elbow and communicating to his box.

The trainer has been called.

Positive signs for Clara Tauson as she gets through her service game without issue.

The clean ball-striking that we saw in the first set is still there and it has to be to get the better of Iga Swiatek, who is looking far calmer now.

Image source, PA Media

Grigor Dimitrov pumps a fabulous forehand winner out of Jannik Sinner's reach and the Italian is looking at his coaching box with increasing desperation.

He's unhappy with an elbow issue - and is asking for the trainer at the next changeover.

Jannik Sinner enjoys the rare comfort of a straightforward hold - and then when Grigor Dimitrov comes in too quickly to the net next game, his pick-up half-volley drifts out.

It's 15-30.... but not for the first time tonight Sinner dumps a backhand lazily into the net - and Dimitrov rubs salt into the wound with a tremendous serve down the T that the top seed has no chance of returning.

A double fault later, though, and we're at deuce. A glimmer of hope for Sinner.

Iga Swiatek holds to love in her opening service game of this second set.

Clara Tauson didn't require the full medical time out but her service game will be a greater challenge to see what health she's in this second set.

Greg Rusedski
Former British number one on BBC Radio 5 Live and BBC Sounds

Jannik Sinner looks nervous, his forehand isn't firing and he is being a bit indecisive. That is very unusual for the Italian. His movement doesn't seem natural on the grass courts, and when you don't feel comfortable with your footing, you just pull off shots ever so slightly.

Grigor Dimitrov has been the better player by far here. He has been picture perfect.

Image source, get

Tim Henman
Former British number one on BBC Two

Sinner is definitely rattled. The first eight points of the second set have gone the way of the Bulgarian so far.

Image source, Getty Images

Iga Swiatek is halfway to the quarter-finals.

A double fault clinches a slightly bizarre first set for the eighth seed against an increasingly exasperated Clara Tauson.

The Dane was shouting up to her box before the first set point then thumped herself on the chest a number of times after giving up a second.

The trainer is out at the end of this set so hopefully she is able to continue.

Eight points in this set so far. All eight to Grigor Dimitrov who hammers down an ace to act as an exclamation mark on this stunning spectacle we're witnessing.

Tim Henman
Former British number one on BBC Two

Dimitrov will be so happy with an early break. Perhaps it is a little bit of a shock to the system for Sinner because he has not been troubled so far. This is a significant lead for Dimitrov now.

When Dimitrov finds that first serve, he is getting himself into rallies. He has got to find those spots and dictate with that first shot.

Jess Anderson
BBC Sport at Wimbledon

What a point that was.

Grigor Dimitrov just sent absolutely everything back over the net.

Groans ring around Centre Court as Jannik Sinner produces a rare double fault to hand Dimitrov break points.

What is going on please?

What is happening?

Jannik Sinner has no answers to the questions Grigor Dimitrov is posing.

A tame forehand into the net at 0-40 and Dimitrov breaks the world number one to love!

Image source, PA Media

Annabel Croft
Former British number one on BBC Radio 5 Live

Iga Swiatek is quite exhausting to watch at the moment because she is being so intense with the way she is shadow swinging in between points and marching all over the court. There is no let up.

She is really bringing the pace and setting the tone for the match, but it looks very stressful the way she is playing at the moment.

Absolutely no let-up from Grigor Dimitrov at the start of set two.

He wins a point he has no right to win with some smart play at the net - and there's an audible gasp on Centre Court when a Sinner double fault hands his opponent three break points...

Greg Rusedski
Former British number one on BBC Radio 5 Live and BBC Sounds

This has already been spectacular!

That is the best set of tennis I've seen Grigor Dimitrov play in a very long time.

Iga Swiatek's turn for a straightforward service game.

Another double fault but at 40-0, it doesn't prove costly.

The eighth seed is now a game away from taking this first set.

Given Clara Tauson has held to love twice and been broken twice so far in this set, I'd say the first point of the next game could be important...