Mark Williams set up a mouth-watering second-round Crucible clash with Ronnie O'Sullivan after completing victory over Liu Chuang.

Two-time former champion Williams was booed loudly by many in the crowd yesterday following his recent derogatory remarks about the World Championship venue, when he called for the tournament to be moved to China.

The heckles returned today as Williams entered the arena.

But the calls from the crowd appeared to be more pantomime than vengeful, and Williams had strong support as he turned a 6-3 lead from yesterday's opening session into a 10-6 victory.

It rarely reached the levels of a serious contest against Liu, a player who beat Jimmy White and then Jamie Cope in the qualifying stage.

Only once Williams reached 9-3 did he stumble, and briefly it seemed a comeback was on when Liu won three consecutive frames, but the danger was soon averted.

Williams accepted his pre-tournament remarks about the venue were out of order, and the 37-year-old regretted them.

"Of course. I've already apologised to the main people I've really upset - the staff and the people in the Crucible," he said. "There's not a lot more I can do really.

"It just came out a little bit wrong. It's not one of my favourite venues, (but) once it goes down to a one-table set-up it's completely different."

Now O'Sullivan awaits Williams, an early collision between two giants of the game. Their best-of-25-frame contest starts on Saturday afternoon.

Williams has never beaten O'Sullivan at the Crucible, and has suffered three defeats to the 36-year-old three-time champion in the past six years in Sheffield.

In 2006, O'Sullivan beat the Welshman in the quarter-finals, while in 2008 and 2010 the defeats for Williams came at the second-round stage.

Williams said of today's success over 21-year-old Liu: "I probably should have won it a lot earlier than that. With every frame he was winning I was starting to come under more pressure.

"At one stage I was in my chair wondering how many more he was going to pull back. I'm over the moon to scrape through."

He is relishing the prospect of taking on O'Sullivan, a player he has a nasty habit of losing to.

"I've been owing him one for 10 years. Let's hope this is the time I beat him," Williams said.

Asked if he enjoyed playing O'Sullivan, Williams said: "If I said yes, and I haven't beaten him for 10 years, I'd be a bit of a liar really. You enjoy the occasion. He always plays well against me. The last time he didn't play too well but still beat me.

"I need to play better than that to have any chance."

Scotland's Stephen Maguire began his second-round tussle with Joe Perry, Graeme Dott's conqueror, tonight and was took a stride towards the quarter-finals as he moved 5-3 clear.

Maguire had to watch Perry fire in 115 to take the opening frame, but a pair of 101 breaks put the 31-year-old Glaswegian ahead, and further runs of 52, 65 and 88 followed, before Perry finished with an 82.

Earlier, Neil Robertson moved 5-3 ahead of David Gilbert in their last-16 match, firing breaks of 76, 84, 109, 57 and a session-closing 131. They resume in the morning and, barring an 8-0 session from Robertson, will play to a finish tomorrow night.

Ali Carter warned Judd Trump his Crucible form cannot last forever as he set up a second-round contest against last year's runner-up by beating Mark Davis 10-2.

Trump began as the title favourite, and the bout of food poisoning which meant he was rather flat during a 10-7 first-round win over Dominic Dale has not altered that status.

Carter, 32, said of Trump: "He's done well. He's riding on the crest of a wave.

"He plays a very open game which is all very well when it's all going well for you.

"When things do turn, which they will, no player can keep a run of form up forever. We'll see how he handles that.

"All of us top players have been about a few years have been on the back of some bad results. And he hasn't had to experience that yet.

"The amount of balls he goes for when he has those battle scars will show us what he's really made of."

Carter, who lost to Ronnie O'Sullivan in his first and only Crucible final to date four years ago, was close to giving up snooker as he struggled to manage his Crohn's disease, an inflammatory bowel condition.

He went as far as approaching Jason Ferguson, chairman of the World Professional Billiards and Snooker Association, to request a year off tour.

But a new approach has given Carter a new rush of energy.

Discussing the symptoms of his medical condition, Carter said: "They have eased off. I've been on quite a strict exclusion diet, I've cut out dairy and wheat, so I'm carrying a lunchbox around with me when I go into restaurants. I feel a bit of an idiot.

"It's taken three weeks and I'm feeling better every day."