Sofia Kenin beats women's seventh seed Coco Gauff 6-4 4-6 6-2
Venus Williams loses to Elina Svitolina after nasty slip on Centre Court
GB's Liam Broady, Jan Choinski and Jodie Burrage through, but Harriet Dart and Katie Swan go out
GB's Dan Evans loses first two sets to Quentin Halys on Court Two before bad light ends play
Men's champion Novak Djokovic defeats Pedro Cachin in straight sets to reach second round
Women's world number one Iga Swiatek beats Zhu Lin 6-1 6-3
Jess Anderson
BBC Sport at Wimbledon
Queues are snaking round Court Two as more and more fans pile in to settle in for an evening of British action.
Katie Swan has got things started and after her we’ll have Dan Evans in action against Frenchman Quentin Halys.
Image source, BBC SportSwan 4-4 Bencic*
Katie Swan can't take her break point opportunity in game seven as Belinda Bencic hits the front, but she's back firing on serve with another ace helping her to an easy hold.
With four games apiece we edge towards the business end of a finely balanced opening set on court two.
Williams 3-4 Svitolina*
Venus Williams is still very much in this, firing a scarcely believable forehand winner deep into the corner to hold.
Image source, EPA*Williams 2-4 Svitolina
Annabel Croft
Former British number one on BBC Radio 5 Live
When Venus connects with the ball she can really get the ball into the corners and push Svitolina into very defensive positions but I have to say everything feels like it has changed quite dramatically sicne that slip.
It looks like Venus isn't sure of her footing on her court, and not the same intensity that she brought out, which was fast and furious at the start of this match.
*Williams 2-4 Svitolina
There's no problem with Venus Williams' serve action, it's the rallies that are the issue.
For now she's able to rely on a couple of aces to get ahead, but a costly double fault brings up deuce.
Earlier a few of you got in touch to tell us you were experiencing longer-than-usual delays in the queue this morning.
Well, the All England Club has commented on those issues.
A spokesperson said: “There has been high demand from members of the public to join the queue on day one at Wimbledon.
“Understandably, our security team on the gates are conducting an enhanced bag check operation. While there has been a steady stream of guests entering the Grounds since gates opened at 10am, entry via the queue has been at a slower rate than in previous years as a result of these checks.
“We sincerely thank guests in the queue for their patience and understanding.”
*Williams 2-4 Svitolina
Sania Mirza
Former Wimbledon doubles champion on BBC TV
Venus is doing a little bit of a side-to-side motion to check her knee out and how it is feeling.
*Williams 2-4 Svitolina
Elina Svitolina is in total control of this opening set now, firing in another winner.
Venus Williams looks at her knee. She winces a little.
Image source, ReutersWilliams 2-3 Svitolina*
Roars from the crowd on Centre Court. Venus Williams is able to stay in a lengthy rally before forcing Elina Svitolina into an error.
30-30. Big point coming up.
Ruud 6-1 5-7 6-4 6-3 Lokoli
Norwegian fourth seed Casper Ruud has made it safely through to the second round.
The 24-year-old, who has reached the final in three of his last five Grand Slam appearances, overcomes France's Laurent Lokoli in four sets, winning 6-1 5-7 6-4 6-3.
Next up for him? British wildcard Liam Broady.
Williams 2-3 Svitolina*
Iain Carter
Tennis reporter on BBC Radio 5 Live
Venus Williams is showing no interest in rallying here. She's just looking to fire off winners as quickly as she can following that fall, and she is resolutely at the baseline.
She was in such control up until that fall.
Kasatkina 6-1 6-4 Dolehide
Eastbourne finalist Daria Kasatkina needed treatment during her match against Caroline Dolehide of the USA, but the Russian 11th seed is through to round two of Wimbledon with a 6-1 6-4 win.
Image source, ReutersWilliams 2-3 Svitolina*
I'm not sure guys. Venus Williams loses her shape as she errors a forehand into the net and hands Elina Svitolina a consecutive break.
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Monty: What a treat to see Venus Williams back on Centre Court playing in the singles at 43! An icon of the game and one of its all-time great champions
Lee: So glad that Venus is ok.
Williams 2-2 Svitolina
Jonathan Jurejko
BBC Sport at Wimbledon
Another supportive roar from the Centre crowd as Venus Williams gets up and carries on.
Think most are surprised she is able to continue.
The scream was sharp and shocking.
Swan 3-3 Bencic*
Ah. Katie Swan had looked so solid on serve in the opening stages on court two, racking up six aces already, but it is a double fault which costs her on break point.
Belinda Bencic calmly responds to her early setback to quieten the crowd, who were already beginning to dream of witnessing a big upset.
Wimbledon 2023: Swiatek lays down marker with brilliant win against China's Zhu Lin
A lot of matches are still ongoing and there's still a lot more to come, so stay with us!
Head to the BBC's Tennis page for more reports, video highlights and analysis on day one of Wimbledon 2023.
*Williams 2-2 Svitolina
No problems there. Venus Williams aces her first serve after her injury.
*Williams 2-2 Svitolina
A very quick game as Elina Svitolina holds to love.
Williams 2-1 Svitolina*
"Come on Venus!"
The five-time champion returns Elina Svitolina's serve into the net before limping across the court.