Katie Boulter hooks a backhand long and Aryna Sabalenka breaks straight back to put this opening set back on serve.

And now two break back points for Aryna Sabalenka at the first time of asking.

Great save from Katie Boulter, an absolute cannon ball that rattles the strings of Aryna Sabalenka. The Belarusian takes control of the next one off a slower second serve and whips a forehand winner into the postage stamp, before following up with another on the run for 15-30.

Kyrgios goes for broke looking for a stunning forehand to get the break. He's aiming right for the corner but it just misses and that's break point number two that's come and gone. One left.

Aryna Sabalenka throws down a double fault and Katie Boulter breaks in the opening game on Centre Court!

A two-handed backhand from the baseline is into the net as Nick Kyrgios misses out on the first of three break points.

Kyrgios has found some dream shots and he has three break points. If he takes one of them, he's serving for the victory.

It's a confident start from the second seed but Katie Boulter does get off the mark with a backhand from the baseline that Aryna Sabalenka can only volley into the tape.

Boulter then scuttles to the net herself and finishes off an overhead smash at the second attempt. Solid stuff from the Brit. 30-30. And hello... what a return, and immediately Boulter has a chance to break.

Mark Woodforde
17-time Grand Slam doubles champion on BBC Radio 5 Live Sports Extra

Kyrgios is a bit of an attention seeker in these early rounds of major tournaments. The further that he goes, though, the tournaments demand more consistency and discipline from a player.

Maybe that's why Nick struggles to get past that quarter-final stage. But he certainly is an attractive player for the fans.

Image source, Getty Images

We go on, on Court One. Humbert has been a couple of shots from victory in both of Nick Kyrgios' last couple of games, but each time the unpredictable Australian has come up with the goods to save himself.

Right then, away we go, Aryna Sabalenka will serve first.

Humbert is again two points from the victory in a Court One epic. A Kyrgios volley at the net, which just doesn't bounce up follows, but the Australian, again living dangerously, pulls one wide. Deuce.

Aryna Sabalenka is the second seed in the women's singles draw but the Belarusian has never been beyond the second round at Wimbledon. Neither has Katie Boulter, so one of this players will be stepping into new territory.

Boulter, ranked 219 in the world, qualified on a wildcard and lost on her only previous encounter with Sabalenka in the Australian Open second round in 2019.

"I lost in two sets. I think it was like one break of serve in each one. I actually thought it was a really good match," said the Brit.

"I'm going to have to serve well, I know that. I'm going to have a swing on her service games. I've got nothing to lose and I'm just going to enjoy the moment."

That maverick Gael Monfils is in deep on court 12.

The world number 17 is into the fifth set against Australia's Christopher O'Connell, who is ranked 130th.

It's tight, with Monfils - now 34 - 5-4 up in the decider and is ready to serve for the match.

For all of his undoubted talent and the entertainment he brings, Monfils has only ever reached round four at Wimbledon.

You can access the match on iPlayer.

Image source, Getty Images

Keith: Another one down! Kyrgios looked like he was seriously injured for a moment but nothing in it. It's been carnage out there this year.

Zayne: How many players have slipped at Wimbledon now?

Osama: Wimbledon is horrible this year the grass is a hell hole for athletes. You’d think it’d be fixed from day one. This is a joke.

Tracy Austin
Two-time Grand Slam champion on BBC TV

First time on Centre Court for both Katie Boulter and Aryna Sabalenka.

Usually you can practice on the day, but not here.

Here is how Cameron Norrie sealed his placed in the second round earlier...

Some missed break-point chances for Murray Sharan to try and get things back on level terms as Cirstea looks to have hold of this first-round match.

Kyrgios is OK to continue after that painful-looking slip, but it doesn't stop Ugo Humbert with a routine hold to again move one game from the second round.

Jonathan Overend
Tennis commentator on Radio 5 Live Sports Extra

He's grimacing and writhing around on the ground, the umpire came scampering down straight away... but he's getting up gingerly now, he looks in discomfort but I think he's going to be OK, thankfully.