Sania Mirza
Former Wimbledon doubles champion on BBC TV

That looked like a hyper-extension. It is a good sign Williams could walk back to her chair without help.

That scream was a shock to the system.

Jonathan Jurejko
BBC Sport at Wimbledon

Awful moment. Venus Williams, who has heavy strapping on her right knee, screams as she falls over near the net. Concerned gasps all round.

Williams is back on her feet and limps to her seat, where she will receive treatment.

Fingers crossed it isn't as serious as we first feared.

We're going to continue. The crowd are right behind Venus Williams who takes a very deep breath.

Image source, Reuters

Over on court two we're witnessing some very impressive serving from Katie Swan!

The Briton closes out a hold in style, landing three successive aces, as she levels at 2-2.

She continues that momentum into Belinda Bencic's next game, a superbly taken forehand helping her to 0-30...

She hangs in a rally long enough to see Bencic miss, sending a break point her way. A huge opportunity in this first set - and she has it! Great stuff.

Venus Williams limps back to her chair. She seems in a lot of pain as she clutches her heavily strapped knee.

She's getting some medical assistance now.

Elina Svitolina breaks back immediately, wrong-footing Venus Williams who seems to twist her knee and screams in pain.

Svitolina wins the point but right now she's full of concern for her opponent who is still down on Centre Court.

Image source, Getty Images

Marion Bartoli
Former Wimbledon champion on BBC Radio 5 Live

Venus has been able to build some momentum this year, especially when she beat Camila Giorgi in Birmingham.

She is very much feeling her grass court game, she is so powerful and playing the angles well, it is a tough task for Elina Svitolina.

Jonathan Jurejko
BBC Sport at Wimbledon

"Five-time Wimbledon champion, that's right," says a bloke holding up his camera phone in the direction of Williams.

The reminder comes after the 43-year-old cracks that backhand winner for the break of serve.

She's still got it.

Canadian 11th seed Felix Auger-Aliassime is involved in a really close battle on Court 12.

His American opponent Michael Mmoh won the first set on a tie-break and the second went all the way as well, with Auger-Aliassime getting the better of that one.

And they're on serve at 3-2 in the third. That one still a lot of miles left on the clock, you feel...

Jan Choinski is going to have to come from behind if he is to win his first main draw match at a major.

The Briton, who switched nationality from Germany to Great Britain four-and-a-half years ago, has lost the first set 7-5, but he's up and running in the second as he opens with a hold of serve.

Image source, Getty Images

Sania Mirza
Former Wimbledon doubles champion on BBC TV

Venus is always so relaxed no matter what the score. She looks exactly the same with a poker face.

And Williams gets over the line, breaking at the first opportunity with yet another backhand winner.

A perfect start for the American.

Venus "James Anderson" Williams brings up break point with a backhand winner.

Jonathan Jurejko
BBC Sport at Wimbledon

Williams won't have to work that knee too much if she's firing down first serves.

One clocked about 115mph and left Svitolina jabbing at the ball like a cautious tailender at Lord's.

Katie Swan is the next British player to begin her campaign.

She's in action on court two, where Dan Evans will follow for his opener against Quentin Halys.

It's a tough draw for the 24-year-old Swan, with Swiss 14th seed Belinda Bencic her first opponent.

That's a good start, though! The Briton, who reached the second round in 2018, fires in an ace to get on the board at 1-1.

Image source, Getty Images

Jodie Burrage wins her first match at Wimbledon - and here is what she had to say:

"Definitely relief. I'm shaking, I can't believe it. That one meant a lot.

"I played some really good tennis and didn't let Caty play and I'm glad I came through some really tough times. I am never going to question a line call again, that was the worst decision but really happy to be able to get through that."

On her injuries and surgeries:

"It hasn't been easy. Three ankle surgeries, fractured knee, stress fracture arm, stress fracture rib - I could keep going. It's been my biggest battle but I've worked really hard the last few years and I'm in a really good place waiting for my run to happen, and hopefully this is the start of it."

Confidence levels coming into Wimbledon after reaching the Nottingham final?

"I gained a lot of confidence in Nottingham. I'm just trying to think about the next match now and then figure everything out after."

Venus Williams holds to 30 as Elina Svitolina hits the top of the net and sees the ball drop on her side.

Much more like it from Venus Williams. After slipping to 0-30 she wins the next two points with forehand winners down the line.

Jonathan Jurejko
BBC Sport at Wimbledon

A warm ovation for the two players as they walked out onto Centre Court.

Williams, who hasn't played here since losing to Garbine Muguruza in the 2017, has a lot of strapping on her right knee and doesn't look to be moving too well just walking.

Svitolina also makes a long-awaited return to Centre, having last played here in the 2019 semi-finals.

Tim Henman
Former British number one on BBC TV

This is going to be tough for Venus. Svitolina has played more tennis recently so she will be the favourite.