Mark Allen said he knew his 147 break was on from an early stage and has described how he held his nerve to make his first tournament maximum at the UK Championship in York.

The Northern Irishman's clearance came in the seventh frame of his second round match against Rod Lawler, putting him 4-3 up. After leaving the arena to compose himself, he then won the next two frames to complete a 6-4 victory.

Allen, a beaten finalist at the Barbican five years ago, came close to a 147 in 2010 at the World Championship, potting 15 reds and 15 blacks before missing the green. He then went on to make a 146 in the same competition.

However, the world number 10 made no mistake against Lawler on Sunday and had been eyeing up the possibility after potting just six balls.

He told the BBC: "It was a big buzz because I'd never made one on tour. The balls were sitting so nice from 24 and I was thinking about it from then. The reds were all sitting, none on the cushions, and you can only mess it up from there.

"I'm very very happy to do it. It was relief when the black went in. I was nervous and I was shaking. I was thinking 'just please pot it because if you miss now you look silly'.

"I went to the toilet afterwards to calm myself down and take deep breaths, control the breathing and take the shakes away. Then I was ready to start the next frame and ready to win the match because you know your opponent is going to make it tough, no matter how well you're playing."

Allen felt the scoreline flattered his opponent a little and felt his margin of victory should have been wider.

"It was a weird match because I felt I played much much better than 6-4," he said. "Rod won a couple of very close frames when he had a better run of the balls. I honestly could've won 6-1 or 6-2 the way I played but he just hangs on and hangs on.

"I'm feeling my game is in good shape and I'm confident and confidence is massive in our game."

Earlier in the day, five-time champion Ronnie O'Sullivan cruised into the third round with a 6-0 win over Rhys Clark.

The young Scot's nerves got the better of him in the opening frame and O'Sullivan capitalised in ruthless fashion, taking a 4-0 interval lead with breaks of 112, 79 and 82.

After closing out the encounter with a stylish 131 clearance, O'Sullivan remained philosophical about his chances of equalling Steve Davis' six titles but admitted there are positive signs that he is rediscovering some of his best snooker.

"I feel like my form is coming back a little bit but it's not the be-all and end-all," he said. "'I'm happy with five but if another one comes along then I'll take it.

"I need to be thinking I want it because if you don't have that ambition and drive then you're not going to win. It's about finding that balance between being care free but also being competitive. I'm playing alright. If it comes it comes, if it doesn't it doesn't."