On table two, Mark Selby who has looked close to his best recently is now three frames clear.

With a break of 82, the Englishman is halfway to the last 16.

Ronnie O'Sullivan takes the third frame.Zhou Yuelong is heavily punished for a miscue.

A break of 71 gets him back to within a frame.

Michael Emons
BBC Sport at York Barbican

Image source, Michael Emons

It is not often when you get to see multiple-time world champions on both sides of the arena divide in the same first-round session.

Mark Selby has twice picked up the UK title in this venue, beating Shaun Murphy 10-6 in the 2012 final and then Ronnie O'Sullivan 10-7 four years later.

The two winners from this afternoon's session will meet each other in the last 16 on Thursday so it could be O'Sullivan v Selby, a pair who have 11 world titles between them.

Alternatively, it could be a match-up between two Chinese players in Zhou Yuelong and Lei Peifan.

There is a record 12 players from China in the UK Championship, the highest figure at a Triple Crown event, and six of that dozen have already booked their spots in the last 16.

This is more like it from Ronnie O'Sullivan. The Englishman has an average shot time of 11 seconds at present and is 70 points to the good.

Zhou Yuelong wins a safety battle on the yellow and goes on to take the second frame.

Ronnie O'Sullivan has work to do.

Mark Selby is not havging around in the second frame and gets enough points on the board to ensure their is no need for Lei Peifan to get out of his chair.

Zhou Yuelong is having problems with the bottom right corner. That's three balls he's missed there already today and by doing so he leaves Ronnie O'Sullivan in.

The Englishman misses a sitter but gets another chance and knocks in a 47 before things go pear shaped.

Zhou has a great chance of going two frames to the good but then can't get position on the yellow.

Over on the other side of the auditorium, Mark Selby is doing Mark Selby things.

He is just the 44 points down so comes to the table and makes a 51 clearance to take the first frame. Granite.

Michael Emons
BBC Sport at York Barbican

The match could not have started any worse for world number 29 Zhou Yuelong as he fouled before a ball had been potted, but Ronnie O'Sullivan failed to take his chances and Zhou gets the opening frame on the board.

There were some interesting comments from O'Sullivan in his interview with BBC TV yesterday, which was broadcast at the top of the programme.

He said: "I’m just enjoying life in general. I have to rely on maybe 12 other players not playing better than me. Maybe four, five or six years ago I would’ve come here and fancied my chances. I have got to hope a lot of people do not perform well to maybe win but it’s just where I’m at at the moment.

“I’ve won a lot of tournaments playing poorly but I feel I’ve played really well this year at every tournament I’ve played.

“If you have to be the best you have to grind it out and that’s not easy to do – but to be a champion you have to learn how to do that.

“He [Zhou] is probably favourite to beat me because he is sharper and played more but we will see what happens. I don’t have anything to prove as in winning tournaments, but I would love to win more tournaments.”

Mark Williams
Three-time world champion on BBC Two

There is always more of a buzz when Ronnie O'Sullivan is playing. It puts his opponent under pressure straight away because you know you have to get off to a flyer otherwise he will steamroller you.

Ronnie O'Sullivan has four opportunities to win the frame but Zhou Yuelong takes the opener.

Zhou misses another red to the bottom right corner. A decent chance for Ronnie O'Sullivan, who rolls in the ired left by his opponent, followed by a black and another red before missing a pink to the left corner by a fair distance.

Ronnie O'Sullivan ekes out a 41-point lead but shortly after running out of position he is put in a snooker by Zhou Yuelong that he can't extract himself from without leaving a red to the bottom left corner. Counter-attack time.

Now Zhou is shaking his head after missing a red to the bottom right corner pocket on 35.

Eight-time UK champion O'Sullivan is able to swerve round the black to knock it in but the white follows the red into the pocket.

Image source, BBC Sport

Michael Emons
BBC Sport at York Barbican

Image source, Michael Emons

There is always something special about the venue when Ronnie O'Sullivan is around - the media room is busier, the fans are queuing up earlier and in greater numbers and there is a big buzz about the place.

But we may have to enjoy it while we can. With O'Sullivan now living in Dubai with his family, he is now far more selective about what events he plays in.

This is his first match in a tournament in the UK since his 17-7 loss to Zhao Xintong in the semi-finals of the World Championship at the Crucible in Sheffield at the start of May.

We also don't know at the moment when his next appearance in the UK will be as he has hinted at missing the Masters in January at Alexandra Palace.

As always, he received a great reception from the fans as he made his way to the arena, minus his cue, which had already been placed on the table waiting for him.

Mark Williams
Three-time world champion on BBC Two

The reason he [Ronnie O'Sullivan] is maybe not winning as many tournaments as he has is that he is not playing enough. For him to get back to winning consistently I think he has to play more but when you are 50 it is hard to play in all the tournaments.

I think his motivation is just winning. He loves to win the big events and even though he has said he doesn't want to overtake Stephen Hendry's record at the World Championship [ O'Sullivan and Hendry are both on seven titles], he does. I think that is is main aim.

BBC Two

Remember you can watch all the action from this afternoon over on BBC Two, BBC iPlayer, the BBC Sport website and the BBC Sport app.

Image source, BBC Sport

We want to hear your thoughts. Who do you want / expect to win the 2025 UK Championship and why?

How far will Ronnie O'Sullivan go? Will he win a record ninth UK title?

Click the 'Contact form' to the left of the page and we will post the best messages in this page throughout the day.

Michael Emons
BBC Sport at York Barbican

Image source, Michael Emons

Welcome to day four of the UK Championship - and what a day it promises to be.

Two of the sport's all-time greats are in action this afternoon with four-time world champion Mark Selby taking on China's Lei Peifan.

And what an occasion it will be on table one as seven-time world champion Ronnie O'Sullivan plays in a UK tournament for the first time since May and faces another Chinese player in Zhou Yuelong.

Image source, Michael Emons

The 2025 UK Championship takes place at York Barbican from 29 November to 7 December.

World number one Judd Trump gets the action under way, with World number five Ronnie O'Sullivan, who celebrates his 50th birthday on 5 December, will feature and bid for a record ninth title - 32 years after his first success.

Other former champions in action include John Higgins, Mark Williams, Mark Selby, Neil Robertson and Zhao Xintong.

The championship is the first Triple Crown tournament of the season, with the other two, the Masters and the World Championship, both taking place in 2026.

You can watch every pot of the tournament live on BBC iPlayer, the BBC Sport website and the BBC Sport app, while there is also extensive coverage on network TV.

You can catch up on all the snooker action here for up to 30 days.

All matches in York are best of 11 frames except for the final, which is played over 19 frames and two sessions.

To see the full schedule & results, click here.