That error by Mark Williams is being punished by Judd Trump, who has got himself in among the reds and is scoring freely.

He will expect to move 6-3 ahead here.

Judd Trump breaks us off in the ninth frame of this match, and the first of this afternoon.

It's not a good break at all, leaving a fairly simple long pot to the bottom left - but Mark Williams misses it and the cue ball spins away into the right middle!

Nightmare start for the Welshman.

Rob Walker is introducing the players to the Crucible crowd now, Mark Williams and Judd Trump are making their walk-ons.

Afternoon play is moments away.

On Thursday, Matchroom Sport president Barry Hearn spoke to BBC TV about the "productive meeting" he had with Sheffield City Council regarding the future of the World Championship at the Crucible Theatre.

The existing deal runs until 2027 and Hearn said there is "still some way to go" before an agreement is reached to extend it.

Steve Sutcliffe
BBC Sport at the Crucible Theatre, Sheffield

The 17 days of the World Championship is the acid test for the top players in the world.

But for those covering the sport for broadcasters and newspapers it is also a serious examination of their wardrobes.

Master of ceremonies Rob Walker says he has five suits with him and has has quite a bit of stuff washed. Not bad considering he's been here since qualifying.

Another journalist tells me he has at least a dozen shirts/tops with him and has had the washing machine on a few times. A colleague from Canada has three pairs of jeans, seven t-shirts, six sweatshirts, a couple of shirts and one three-piece suit.

In case you're just joining us, semi-final matches are best of 33 frames.

So it's first to 17 wins - there's a long way to go in Trump v Williams.

Ken Doherty
1997 world champion on BBC Two

Judd Trump has really developed his game over the past few years. He's been the dominant snooker player. You can see he has worked on different parts of his game and can play any type of game.

MC Rob Walker is currently warming up the Crucible crowd here at the World Snooker Championship - he is the man who also interviews the players and has successfully turned his hand to commentating at the Crucible.

He is one of the busiest people involved in the tournament - as we can see in this 'day in the life' video that takes us behind the scenes in Sheffield.

Ken Doherty
1997 world champion on BBC Radio 5 Live

I think Mark Williams and Judd Trump struggled with the table yesterday. It was very humid yesterday and the atmospherics can have an impact on the way the table plays. It wasn't conducive to big scores and breaks and there were a few scrappy frames. In the end they got it together and made a century each and Judd Trump will be delighted to have a two-frame lead heading into today.

Mark Williams was involved in a classic quarter-final against John Higgins on Wednesday, coming through a thrilling deciding frame on the final black.

Will he need more moments like this to upset Judd Trump?

Ken Doherty
1997 world champion on BBC Two

Mark Williams against Judd Trump was a bit of a war of attrition in the early parts last night, but there were a couple of lovely centuries as well. Trump was massive favourite going into this match but you cannot discount Williams, one of the icons of the sport.

On Thursday evening, world number one Judd Trump opened up a 5-3 advantage over three-time winner Mark Williams in their first meeting at the Crucible since their thrilling semi-final in 2022.

Fifty-year-old Welshman Williams, who is the oldest player to reach the last four since his compatriot Ray Reardon featured as a 52-year-old in 1985, compiled breaks of 73 and 116 as he shared the opening four frames with 2019 champion Trump.

Trump, who has won three tournaments this season including the Saudi Arabia Masters, where he pipped Williams in a decider, took the first frame following the mid-session interval after making 52.

And while his opponent again responded, the 35-year-old Englishman won an edgy seventh frame and punished Williams for missing a black off its spot to claim a two-frame cushion overnight by knocking in his 105th century of the season.

Kwong Tse: An 8-0 session whitewash for Zhao against Ronnie. It is very sad to see but it looks like the pupil will outclass his master. Zhao looks like wrapping this up with a session to spare. Could today be the last time we see Ronnie at the Crucible?

Steve Moss: He hasn't been in the best of form healthwise or cuewise but Ronnie did wonders to make the semis. Zhao looks awesome & Trump or Williams will have to find the best form of their lives to stop the Chinese dynamo.

Mark O'Connor: A changing of the guard.

Image source, Getty Images

Did the morning session's Crucible audience, and the millions watching in the UK and worldwide, witness a pivotal moment in snooker history?

John Virgo thinks that might be the case, as Ronnie O'Sullivan was so comprehensively outplayed by Zhao Xintong.

• Click to read Steve Sutcliffe's report

With his 50th birthday coming up in December, perhaps the days of O'Sullivan taking World Championship semi-finals by the scruff of the neck have gone.

O'Sullivan has won world titles in 2001, 2004, 2008, 2012, 2013, 2020 and 2022, putting him level with Stephen Hendry's modern era record of seven victories on the biggest stage.

Assessing Zhao's destructive performance, Virgo said on BBC Two: "What a player. What a future he's got in the game. To do this to Ronnie O'Sullivan, well it's a phenomenal performance.

"A changing of the guard maybe, right here, right now."

In case you're wondering what we meant by blow-out in our 2pm entry, and you missed the morning session - blimey Charlie, it was something.

Zhao Xintong produced a scintillating display of potting to open up a 12-4 lead against seven-time champion Ronnie O'Sullivan in their World Championship semi-final.

With the overnight score at 4-4, Zhao took all eight frames on Friday morning to become only the fourth player to win a session 8-0 against O'Sullivan at the Crucible.

Zhao, a former UK Championship winner who is competing as an amateur, was clinical among the balls and delivered the sort of performance that suggests he may be ready to become the first player from China to take the title in Sheffield.

The 28-year-old compiled breaks of 112 and 115 as well as five other half-centuries to take complete control of the contest, earning a standing ovation from an appreciative Crucible crowd.

Their match resumes on Friday evening at 19:00 BST, with Zhao requiring five frames to reach the final.

BBC Two

Our TV coverage has just resumed on BBC Two, running through until 18.00 BST this evening.

You can follow by clicking the 'Watch Live' button at the top of this page, via BBC iPlayer, or on the good old fashioned tele box.

14:30

• Judd Trump v Mark Williams (frames 9-16)

19:00

• Ronnie O'Sullivan v Zhao Xintong (frames 17-24)

Hello again - we're back at the Crucible to bring you the Friday afternoon session, featuing a finely poised semi-final between Judd Trump and Mark Williams.

Will we see another tightly contested eight frames - or will we see another blowout, as we witnessed this morning?

We're going to pause our live text commentary following a frenetic morning where Zhao Xintong recorded a session whitewash over Ronnie O'Sullivan to put one foot in the semi-finals.

Be sure to read Steve Sutcliffe's report from the Crucible Theatre in Sheffield on what's happened so far today...

We will be back at 14:00 BST for the afternoon session of the other semi-final where Judd Trump leads Mark Williams 5-3, with live coverage of the match on BBC Two and via the iPlayer.