Ken Doherty
1997 world champion on BBC Radio 5 Live

Ronnie O'Sullivan looked all at sea and no confidence whatsoever in what he was doing. If Ronnie can get some inspiration from the first or second frame tonight he could go on a run and win frame after frame.

Hopefully he can come out tonight with the crowd behind him. It only takes one break and it could set him on a roll. He has to win the session at least 5-3 or 6-2. That would give him some sort of chance.

Looking at Ronnie O'Sullivan in the morning session sat in his chair, he's looked devoid of any sort of confidence. I wouldn't rule him out but he'll need a big performance.

Jamie Broughton
BBC Radio 5 live

Ronnie O’Sullivan is still struggling with his cue, despite changing the tip and the ferrule on it yesterday.

But take nothing away from Zhao Xintong, who played some brilliant snooker in the session.

Zhao won the opening four frames with breaks of 57, 112, 82 and 57 in barely three quarters of an hour to lead 8-4.

And after the mid-session interval, the Chinese star then won the next four - with a century - the highlight, to extend his lead to 12-4.

The target for victory is 17 - O’Sullivan needs a fast start to have any chance of turning the match around.

This was only the fourth time that Ronnie O'Sullivan had lost a session 8-0 at the World Championship - a tournament he has appeared in every year since his debut in 1993.

We've just witnessed the second session of an extremely close semi-final between Judd Trump and Mark Williams.

This morning, Zhao Xintong won all eight frames against Ronnie O'Sullivan to take a 12-4 lead against the seven-time world champion.

If Zhao wins five of tonight's scheduled eight frames, he will be into his first Crucible final with a session to spare.

There's been plenty of reaction to that astonishing session of snooker - we'll bring you some of the stats and what our BBC pundits had to say between now and the start of their third session at 19:00 BST.

You can catch up with all that's happened so far on day 14 of the World Snooker Championship in Steve Sutcliffe's report from Sheffield.

And there's still one more session to come today...

Ashley Parker: Having been 7-3 down to go on and end the session all square at 8-8 Mark Williams will be delighted! Great fight back from Willo! Game on now!

Ryan Glendenning: What a tightly contested semi-final this has been between Mark Williams and Judd Trump. Two semi-finals with two completely contrasting outcomes. This one could get either way while the other one is Zhao Xintong's for the taking.

Joseph Hadfield: Contrast that with this afternoon’s affair. Judd Trump and Mark Williams can’t be separated. 8-8 going into tomorrow’s third and fourth sessions. Mouth-watering. Could potentially be the only sessions on Saturday.

Stephen Hendry
Seven-time world champion on BBC Two

Judd Trump had a chance to go 8-3 up - if he had, he might of steamrolled the session.

But you can't get rid of Mark Williams. Ever.

There was something for everyone in that session. Absolutely gripping snooker.

Stephen Hendry
Seven-time world champion on BBC Two

Tomorrow morning, can you get a lead into the night? I can't see there being more than two frames between them.

Steve Davis
Six-time world champion on BBC Two

Absolute carnage. Amazing snooker.

Mark Williams looked edgy early on, but as the session panned out he got calmer and calmer. Judd Trump must be wondering what is going on - it's not his fault, but Mark Williams is playing the best snooker he has all week.

Dennis Taylor
1985 world champion on BBC Two

A standing ovation for both players as they leave the Crucible. Unbelievable snooker. Well done boys!

A break of 96 from Mark Williams as he clears the table to bag the 16th frame. A shake of the hands between the players, with the emotion and fervour left to the crowd.

Absolutely superb from the 'Welsh Potting Machine' in that session.

All square going into tomorrow's final two sessions.

John Parrott
1991 world champion on BBC Two

If Judd Trump didn't know it at the start of this match, he does now - he will have to go through the wringer to get past this fella.

What a session from Mark Williams who has shown tremendous determination. He floats a tricky pink into the middle pocket and the Crucible roar with approval. He's 67 ahead now with 59 remaining.

Judd Trump not quite able to execute the tactical stuff and Mark Williams is able to get back in among the reds, which are a little more open now.

With the black stranded on the cushion he's having to work the pink. A chance to close out the frame here and get back on terms for Williams.

Steve Davis
Six-time world champion on BBC Two

Fantastic tactical play from both players, that is what makes snooker so fascinating. What other sport can keep you on the edge of your seat when nothing is happening?

You feel Mark has his composure back, he fancies himself. If Judd gets out 9-7 ahead, he will feel he has done a miracle.

Mark Williams has shown real character in this session. He's made a positive start to the 16th frame, and final one of afternoon, with a break of 30 but is unable to break up the pack when potting the blue and elects to play safe.

Judd Trump lifts himself from his chair.

Stephen Hendry
Seven-time world champion on BBC Two

This is why Mark Williams is my hero. After all that safety, a 35-minute frame, and he still has the talent and composure. Magnificent.

Dennis Taylor
1985 world champion on BBC Two

What bottle this Welshman has! An unbelievable finish to that frame and we have a cracker on our hands.