Snooker - World Championship Update:Ronnie O'Sullivan set up a second-round clash with Mark Williams by stumbling over the finish line in his World Snooker Championship opener against Liang Wenbo at the Crucible.
Favourite O'Sullivan looked in trouble at the Sheffield venue after letting a 9-3 lead dwindle to 9-7. But a break of 73 in the 17th frame saw him clinch his place in the last 16.
As with his performance yesterday, O'Sullivan played outstanding snooker in spells but for long stretches he looked almost disinterested even when at the table.
"I just didn't get going today and he played all right towards the end, he looked quite dangerous in the last two or three frames," O'Sullivan said.
"The pressure was getting on me a bit so I had to find something from somewhere.
"The nerves play a big part here and unless you settle and find your rhythm then it can be tough out there."
Liang had edged the opening frame of the afternoon to cut O'Sullivan's lead and he should have had the next from 60-7 in front.
A run of 20 from O'Sullivan cut the lead, before he missed a red and grumbled under his breath to himself.
But after Liang failed to inflict any punishment, O'Sullivan produced a magnificent 34 clearance, despite the positioning of the balls making it look highly improbable.
The three-time world champion took the next frame comfortably, despite a refereeing blunder at its finale when Colin Humphries went to pick the black from the pocket but instead picked out a red.
As O'Sullivan played his next shot, Humphries was frantically searching for the black, and a foul was called, halting the break.
O'Sullivan was not impressed, but when Liang cut the deficit to 9-4 with a 61 break it only looked like brief resistance.
He followed that up with 103 after the resumption, and then made it 9-6 after a frame in which both men played twitchy snooker.
Suddenly there was a glimmer of hope for Liang, more so when he fired in 127 - the highest break of the tournament so far - to go 9-7.
But then the door was shut on his hopes, O'Sullivan taking his chance to set up his clash with Williams.
"It'll be a good game because I don't think you can get a harder draw than Mark in the second round," O'Sullivan said.
"He's coming back to form and other than John Higgins he'd probably be favourite.
"He's probably the only player that can beat John if John's playing well.
"I think Mark's the only player that could find the game to win against him, so it's a really hard draw, he's playing well at the moment so I could have done with an easier match really."
In the day's other action Mark King holds a slender 5-4 lead over six time champion Steve Davis, who is making a record 30th appearance at the Crucible.
Ireland's Fergal O'Brien trails 6-3 against Australia's Neil Robertson, while former champion Peter Ebdon takes on Graeme Dott this evening.