RESULT: Ronnie O'Sullivan 7-17 Zhao Xintong
China's Zhao into first final, beating seven-time champion O'Sullivan with a session to spare
END OF SESSION: Judd Trump 8-8 Mark Williams - resumes at 10:00 BST on Saturday
Semi-final matches are best of 33 frames
O'Sullivan 6-12 Zhao
Stephen Hendry
Seven-time world champion on BBC Two
Usually in this championship, when Zhao has been in this position, he's scored heavily. But this is a different situation now tonight.
He's just losing the cue ball and not flowing yet, he's not in a rhythm and a bit tight.
O'Sullivan 6-12 Zhao
Zhao looks set to launch a big break, up to 37, splits the pack... misses the pink to the left middle.
But O'Sullivan then misses the easiest red you'll see all night, it wipes its feet on the bottom left pocket then bounces out. Ronnie lowers his head to the baize, disconsolate.
O'Sullivan 6-12 Zhao
Start of frame 19, and O'Sullivan hands eight points to Zhao after the man from China tucks the cue ball skilfully behind the green.
O'Sullivan eventually gets out of it but leaves Zhao with a good chance to make a big score.
O'Sullivan 6-12 Zhao
Shaun Murphy
2005 world champion on BBC Two
We've seen more easy balls missed in the first two frames tonight [by Zhao] than he's missed all tournament.
The black off the spot was the easiest and most costly of them all so far. If he pots it, he wins the frame.
O'Sullivan 6-12 Zhao
A moment of confusion after Ronnie O'Sullivan cleverly snookers Zhao Xintong, who is on the brown. Zhao misses his shot, but O'Sullivan didn't hear the referee call a "miss" and comes to the table - before apologising and sitting back down, allowing Zhao to have another go.
When he returns to the table for real, O'Sullivan pots the brown and the blue to win the frame.
The gap is down to six.
O'Sullivan 5-12 Zhao
Image source, Getty ImagesA snooker escape from Ronnie leaves the green over the pocket, but the brown is right next to the cushion.
Zhao attempts a pot into the bottom left - and it just comes off the lip of the pocket.
This is tense.
O'Sullivan 5-12 Zhao
Ronnie O'Sullivan, for a moment, looks like he's back to his best with a slick break to move ahead in this frame.
But an error sees him tie up the yellow and blue next to each other, and an attempted trick shot to pot the yellow doesn't come off.
This frame will go down to the wire.
O'Sullivan 5-12 Zhao
Stephen Hendry
Seven-time world champion on BBC Two
One thing Zhao has not done for pretty much the whole World Championship is miss a black off the spot.
That will give Ronnie huge encouragement.
O'Sullivan 5-12 Zhao
Well, Zhao makes a smooth break of 36 - but, attempting a cannon into the reds after potting the black off the spot, he thinks too far ahead and ends up missing what should have been a simple pot.
Over to you, Ronnie...
O'Sullivan 5-12 Zhao
A call of "settle down please" by Leo Scullion after Zhao Xintong misses a wild red, the ball springing into the air off the cushion.
But O'Sullivan misses the follow up, an attempted long red - those have been a problem for him over the last two weeks.
A good chance now for Zhao.
O'Sullivan 5-12 Zhao
Shaun Murphy
2005 world champion on BBC Two
Referee Leo Scullion has a job on his hands tonight because the crowd are going to make themselves like a 12th man out there and they are going to make themselves heard.
Zhao just looks like he might be just about to realise what he's almost achieving here and it could be a case of rabbit in the headlights - a long way to go, but the signs are there.
O'Sullivan 5-12 Zhao
Zhao badly miscues an attempted long red, but has a moment of fortune as the cue ball runs safe near the baulk cushion.
If you can't be good, be lucky.
Then on his next visit, he is good with an excellently played red into the bottom right, almost slicing the bottom off the black ball.
O'Sullivan 5-12 Zhao
Ken Doherty
1997 world champion on BBC Two
He needs a fast start. We thought when Ronnie missed the black that Zhao was going to pick up where he left off this morning.
But for the first time, we've seen a bit of evidence of maybe a bit of Crucible nerves creeping in.
O'Sullivan 5-12 Zhao
Ronnie clearly isn't happy with his play again tonight, but a break of 37 is enough to win the first frame of the evening.
One down, seven to go for O'Sullivan.
O'Sullivan 4-12 Zhao
Image source, PA MediaZhao seems to have things set up for a decent break, but he misses a regulation red into left middle. The man from China has not yet hit anywhere near the heights we saw this morning.
Big chance now for O'Sullivan to take the frame.
O'Sullivan 4-12 Zhao
Stephen Hendry
Seven-time world champion on BBC Two
Not once in that little break did he have the cue ball where he wanted it for two shots in a row.
O'Sullivan 4-12 Zhao
Ronnie O'Sullivan settles into the table now, a little run of scoring to ease the nerves.
The cue ball is still not lying perfectly for him though - perhaps a few of those cue issues are persisting from earlier.
And a break of 36 for Ronnie ends as he misses a difficult black, after the white ball was left in a tricky spot. Far from flowing.
O'Sullivan 4-12 Zhao
Stephen Hendry
Seven-time world champion on BBC Two
A little bit of an edgy start to this frame from Zhao Xintong. He hasn't hit a shot properly yet.
O'Sullivan 4-12 Zhao
What is going on here? Zhao has potted the cue ball now, skewing it in while trying a regulation safety.
Some odd shots early on here, both men perhaps rather nervous.
O'Sullivan 4-12 Zhao
The first potted ball of the night is a long red by Ronnie - but he's snookered himself in the aftermath!
O'Sullivan misses the brown on his first attempt at the safety, before catching it on the second try.
13 points registered so far by both men, 12 of them through fouls.
