No room for error here for Ding Junhui.

He's five points behind Luca Brecel but we're into an early safety exchange with reds scattered across the table.

Can Pang make this scoreline respectable, then?

He was in touch at 6-4, remember, before O'Sullivan's six-frame burst yesterday.

The Chinese player starts with a good long red but breaks down on 12.

Ken Doherty
1997 world champion on BBC Two

Ronnie's been good in this tournament but he's not been at his best.

But nobody's really scratched the surface, put him under any pressure.

He's not been tested but there have been good signs for Ronnie.

Sam: We could be in for one of the shortest sessions of snooker ever or we could be in for one of the greatest sessions of snooker ever - I think spectators with tickets for tonight’s matches will be hoping for the latter.

A quick look then at how the last-eight draw is panning out.

The four quarter-finals will, like the second-round matches, be played over three sessions and are the best of 25 frames.

They will take place on Tuesday and Wednesday.

• Zhao Xintong v Chris Wakelin
• Ronnie O'Sullivan/Pang Junxu v Si Jiahui
• John Higgins v Mark Williams
• Luca Brecel/Ding Junhui v Judd Trump

Image source, Getty Images

World number one Judd Trump held off Shaun Murphy's fightback to win an epic last-16 tie and move into the quarter-finals of the World Championship.

Trump looked set for a routine victory when he led 12-6 but missed a red into the middle pocket and Murphy capitalised by reeling off four frames in a row.

However 2019 champion Trump held his nerve to take the 23rd frame for a 13-10 win and set up a match against either 2023 winner Luca Brecel or 2016 runner-up Ding Junhui in the quarter-final.

In the other match in the afternoon session, China's Si Jiahui moved into the quarter-finals thanks to a 13-10 win over England's Ben Woollaston, who had eliminated fourth seed Mark Selby in the first round.

In the quarter-finals, Si will play either Ronnie O'Sullivan or Pang Junxu, with O'Sullivan holding a dominant 12-4 lead.

Steve Davis
Six-time world champion on BBC Two

Ronnie has been very controlled so far this tournament - he's hasn't hit top gear but he hasn't had to. He looks in good shape.

Michael Emons
BBC Sport at the Crucible Theatre

Image source, Michael Emons

Here were Ronnie O'Sullivan and Pang Junxu arriving at the Crucible not too long ago.

The Rocket only needs one frame so can he make this a quick night's work and blast his way into the Crucible quarter-finals?

Image source, Michael Emons

Image source, PA Media

Luca Brecel was at his brilliant best on Saturday against Ding Junhui and the 2023 champion followed that up with another fine display on Sunday to move within one frame of the quarter-finals.

In fact, it took centuries in frames 15 and 16 from Ding to prevent Brecel winning with a session to spare.

Surely, though, that was just delaying the inevitable.

A mouth-watering last-eight tie with Judd Trump awaits if Brecel can complete the formalities this evening.

Image source, PA Media

Ronnie O'Sullivan is one frame away from reaching the World Championship quarter-finals on his return to snooker after a three-month absence.

Having trailed 6-2 after the first session, Pang Junxu won the first two frames they played on Sunday to reduce his deficit to two.

But then O'Sullivan went through the gears, rattling off six frames in a row to move to the brink of victory and a quarter-final against another Chinese star, Si Jiahui.

He'll want to get things polished off very quickly indeed and not waste too much energy with potentially three more big matches ahead this week.

Here's how today's two final second-round matches are looking as they get set to come to a conclusion.

Every chance it will be a short evening - but if it's a long one, it'll be memorable.

19:00 BST

• Ronnie O'Sullivan 12-4 Pang Junxu
• Luca Brecel 12-4 Ding Junhui

BBC Two

And... we're back.

Play is about to resume in Sheffield, with coverage starting on BBC Two at 19:00 BST.

Both matches are available to watch live on the BBC iPlayer and via the "Watch and listen" tab at the top of this page.

Image source, Getty Images

OK, that's the afternoon session done with.

We'll be back tonight as two of snooker's speedsters - 'Rocket' Ronnie O'Sullivan and 'Belgian Bullet' Luca Brecel - race to see who'll be first over the finishing line.

Both hold 12-4 leads over Pang Junxu and Ding Junhui respectively so each will be hoping for early nights to conserve the energy for battles ahead.

Or will we witness a comeback for the ages? Join us back here at 19:00 BST to find out.

Stephen Hendry
Seven-time world champion on BBC Two

I expected Si to have come on a bit more because he was really impressive in that [2023] World Championship.

I thought this was a guy for the future, a real prospect. But his actual game, I don't think has come on as much as I thought it would.

He's going to be tested against O'Sullivan - but he's got nothing to lose so enjoy it.

Image source, Getty Images

Si Jiahui speaking to BBC Two:

"I'm really happy that I won this game but I think it's the worst match I played at the Crucible ever. I think my opponent was not performing at his best.

"I think back in 2023 [when Si reached the semi-final] I was a more accurate player and playing with a better mindset. It was very pure, I was not over-thinking. I think I need to learn from my past to just play the match."

Defeated Ben Woollaston speaking to BBC Two:

"The first session and a half I didn't really turn up to be honest, I had so many chances. I played better today but Si did really well the last three frames.

"I could have played better in both matches but this experience will be good for me going forward next season and the coming seasons.

"I've never experienced session after session, these long days. It's disappointing at the moment but it's been a good couple of weeks for me."

John Parrott
1991 world champion on BBC Two

It was nervy from both players. The first time Ben has played a best of 25, the furthest he has got in the competition.

For Si Jiahui, who would have been expecting to face Mark Selby, the pressure reverted onto him, as he would have been favourite to win.

He got over the line and he'll just be relieved to get into the quarter-final.

And there it is - fairly routine blue and pink to follow the fantastic brown.

Si Jiahui is into the World Championship quarter-finals for the second time in three years.

He beats Mark Selby's conqueror Ben Woollaston, finally pulling away in the final stretch of that last-16 tie.

With seven-time champion Ronnie O'Sullivan 12-4 up against Pang Junxu, it's likely the 'Rocket' who'll be next up for Si.

Ben Woollason has had his chances in this frame and misses a tough but gettable cut on the brown.

Si Jiahui thumps in an equally 50-50 pot... it's almost over...

Now level at 36-36 but Woollaston's only option is a safety on the brown.

He knows any error here could be his last at the Crucible this year.

Si Jiahui - with that two-frame advantage - goes for an outrageous double on the brown that is soooooooooo close. Nails being bitten aplenty!