After a few early opening salvos in the second frame, China's Zhou Yuelong has seized the upper hand in his match against fellow countryman Xiao Guodong.

Zhou produced a smart clearance with a break of 53 - the highest of the match so far - to establish a two-frame cushion.

Xiao has work to do here.

Michael Emons
BBC Sport at the Crucible

Image source, Michael Emons

Antoni Kowalski is leading against three-time world champion Mark Williams at the Crucible - but at the start of the month the 22-year-old would have been fearing for his snooker future.

Ranked 69th in the world, he needed to nudge himself into the provisional top 64 to save his snooker tour card - and effectively keep his professional career.

He had to come through three qualifying rounds, beating Connor Benzey 10-1, Joe O'Connor (who beat Mark Selby at the Crucible in 2024) 10-8 and Wales' Jamie Jones 10-8.

An emotional Kowalski was in tears after the victory over Jones as he became the first Polish player to qualify for the Crucible.

"I never cry, so that's the perfect explanation of what it means to me," he said afterwards. "I'm going to realise one of my biggest dreams and play at the 'Theatre of Dreams'.

"I'm not based in the UK so it is more special, and my girlfriend and my parents will come to the Crucible. At the end of the first session and beginning of the second I was absolutely gone, then I stopped thinking, turned off my brain and just played."

A measured opener from Zhou Yuelong who has clinched the first frame against his Chinese compatriot and friend Xiao Guodong.

Xiao did not get a point on the board after Zhou backed up three breaks of over 30 with some clever positional play.

Xiao is 15 places above Zhou in the world ranking at number nine but the latter has been in good form recently.

Debutant Antoni Kowalski produces some impressive shots to take the first frame 82-0.

The Polish youngster pounced on a slip up from Mark Williams, but his break looked set to end at 68.

The white is practically touching a red, but Kowalski does brilliantly to reach it using the spider rest while practically climbing onto the table to pot.

After cracking a smile when Kowalski pulled off his trademark 'back-to-front' shot, Williams concedes.

Image source, Getty Images

Last year's finalist and three-time world champion Mark Williams begins his title-tilt against debutant Antoni Kowalski.

The 'Flying Pole' came through four rounds of qualifiers to save his tour card and become the first Polish player to reach the Crucible.

Poland is the 21st country to be represented at the Crucible.

At 22 years old, Kowalski is the same age as Williams' son.

He was first spotted by the late Brandon Parker, former manager of Shaun Murphy, and at 12 years old received a table through the Paul Hunter Foundation so that he could practice under professional conditions.

Stephen Hendry won five straight World Championships from 1992 and 1996.

No player has a longer streak of winning the tournament since the move to the Crucible in 1977.

Steve Davis
Six-time world champion on BBC Two

Zhao has not stamped his authority on this match because he's not played well. He's let Liam back into this match, enjoy it and look comfortable.

Zhao Xintong will take a slender lead into the evening session.

Liam Highfield puts himself in a tricky spot with the cue ball nestled up against two reds, but he manages to sneak the black in.

But then he doesn't quite get the angle on a set-up shot for a red on the cushion, and can only watch as it bounces around the pocket and stays out.

That miss allows Zhao back in, but after sinking yellow and green he misses the brown, albeit with Highfield needing a snooker.

Highfield thinks he's got one, but Zhao manages to swerve around the black. He gets a stroke of luck as a double kiss on the pink prevents the cue ball dropping into the pocket.

It feels like that frame was Highfield's for the taking.

This match will resume in tonight's session (19:00 BST).

Lee Walker
Former World Seniors champion on BBC Two

That was a must-win frame for Mark Allen and he has won it. Overall, a fabulous session of snooker

Mark Allen edges himself to 64-36 in front and with the table very much still alive he's forced into some defensive play.

The remaining reds are nestled behind the yellow on the baulk cushion and with the pink and blue obscuring the path Zhang Anda manages to negotiate a tricky double.

However, China's Anda later fouls when he knocks the yellow in after potting a red and ends up conceding the frame shortly after.

Northern Irishman Allen cuts the deficit to two frames.

Michael Emons
BBC Sport at the Crucible

A few chuckles and a round of applause for referee Rob Spencer as he announces that this is the final frame of the session.

He had incorrectly said the same thing a frame ago, at the start of frame eight, before being quickly corrected by the players.

Many players said Zhao Xintong was the favourite to win this tournament, but the reigning world champion will be hoping to claim this frame to ensure he holds a slim advantage.

It could well be a dramatic night when these two play to a finish from 19:00 BST in the evening session.

Image source, Getty Images

• Came through four rounds of qualifying to reach Crucible for first time since 2022
• Broke his wrist in an e-scooter accident in 2023, forcing him to drop out of the pro tour for a year
• Has never progressed beyond the first round in Sheffield
• Won two amateur finals in 2025, including EBSA European Snooker Championship
• Plays left-handed

Game on!

Zhao Xintong continues to wobble and Liam Highfied draws level in this topsy-turvy encounter.

The 35-year-old from Swindon makes a half-century break, before Zhao concedes at 71-23.

Zhao has been caught yawning an awful lot during the last few frames - he'll need to perk up a bit for the second session of this match this evening.

Image source, Getty Images

• Turned professional in 2009 after winning Asian under-21 title
• Emulated Stephen Hendry and Ronnie O'Sullivan by qualifying for the Crucible in his first season in 2010

• Won first ranking title of his career at 2023 International Championship, making a 147 break in the final
• Impressed during two rounds of qualifying earlier this week
• Has never progressed beyond the second round

Ken Doherty
1997 world champion on BBC Two

He's all over the place at the moment, Zhao Xintong.

Zhang Anda produces a break of 72 and Mark Allen concedes the seventh frame.

Zhang is just playing very, very well and there is little Allen can do about it.

Well then, Liam Highfield refuses to let go of this match.

The Englishman makes several mistakes, but so does Zhao, as Highfield wins frame seven.

The defending champions does not look comfortable at all and keeps leaving himself open.

This has been a strange match with lots of unforced errors.

If you're watching BBC Two and wondering why the Crucible has turned into a rugby pitch... you need to change the channel.

Switch over to BBC One to continue watching Zhao Xintong v Liam Highfield.

Zhang Anda produces a break of 58 to move 4-2 ahead.

Mark Allen looked to be in control of that frame, but once he let Zhang in that was it.

There's a long way to go, but Allen is up against an opponent who has brought his qualifying form to the big stage.

Could Allen be looking at his first first round exit as a seeded player since 2020?