The Masters 2010 Venue: Wembley Arena, London Dates: 10-17 January Coverage: Live on BBC Two, BBC Red Button and BBC Sport website
Video - Cheeky O'Sullivan fouls after century
Ronnie O'Sullivan won a high-quality match against Neil Robertson 6-4 to reach the last eight of the Masters.
Robertson went 3-0 up but O'Sullivan - who declared himself underwhelmed by his own performance - gained a vital foothold with a 114 break.
The former world champion pulled level with a break of 87 in the sixth before scores 106 and 76 sealed the win, despite a break of 140 from Robertson.
Mark Williams also progressed with a 6-3 win over Ali Carter.
The Welshman prevailed in a scrappy encounter as both players squandered excellent opportunities after the half-time interval.
Video - Robertson loses despite 140 break
The world number 15 had been struggling with a neck injury following a car crash on Monday night, but was fit enough to take his place at Wembley on Tuesday.
"Someone rammed up into the back of us and that sort of did my neck in a little bit," Williams told BBC Sport.
"I had a sore neck virtually straight away."
Carter had been in good form in the opening exchanges with the match locked at 2-2 at the interval, but the world number five lost his momentum soon after as Williams took control.
Although Carter managed to level at 3-3 in the sixth, Williams nailed the next three to clinch the match.
Sore Williams overcomes Carter
Meanwhile, O'Sullivan, who plays Peter Ebdon in the quarter-final, suggested his current form was a shadow of that which has seen him lauded as the most talented player the sport has ever seen.
"I'm not the player I was when I was 15 or 16. A lot of the time I'm playing sub-standard shots. Now and then I catch hold of one and play a killer shot.
"The only time I play a pure shot is left-handed. The last time I played a good tournament was the (2003) European Open in Torquay and the Irish Masters a couple of weeks later.
"I don't want to have to rely on the occasion of being 3-0 down in front of a big crowd to salvage some pride. I can't pot a ball in practice.
"My attitude will be the same in my next match - I won't be surprised if I win or lose."
For O'Sullivan, the victory over an in-form Robertson did little to give him hope of recapturing his best.
O'Sullivan talks thongs with BBC team
"I wasn't surprised to be 3-0 down," he told BBC Sport.
"It was just nice to score a few in the end so I could make a game of it as it could have been a whitewash.
"I didn't panic. You can't panic, that's rule number one, because if you panic it's a disaster.
"I made just two out of 10 long pots, and I think Neil will be disappointed to have beaten someone making just two of 10 long pots."
"I'd give my long potting two out of 10. It's hard to get excited.
"To make two or three centuries in a match is not a big deal, that's how the modern game is. I would have accepted winning or losing today.