Ronnie O'Sullivan holds nerve to open Masters defence with Liang Wenbo win

Defending champion O’Sullivan was 5-4 down as the Chinese cueman won three straight frames to overturn a 4-2 deficit.

And the best-of-11 contest reached the decisive frame, when O’Sullivan recorded his best break, of 121.

“You’ve got to feel for Liang,” admitted O’Sullivan. “He should have won that match. He should have put me away.

“I don’t think I was much of a fight throughout the whole match, I just managed to nick a few frames through my experience.

“Maybe that was the difference. I didn’t feel very good in myself. I’ve had a bit of a virus. I just felt really lethargic, really tired. So it was difficult to really feel like I wanted to hold a cue, let alone try and compete and win a match in probably the most competitive tournament we have.

“Hopefully in the next couple of days I can shake off this bug and feel better. I’m a bit of a momentum player so when I get on a roll I can flow, but when I feel like that, it’s hard.

“I don’t think your B and C game can win you tournaments these days. It might win you the odd match here and there. If I’d have lost there, I’d have been happy just doing a bit of punditry work because I just like being at tournaments, having a laugh with the lads.

“Liang’s a good competitor, he’s a very good player. He’s a winner now and I’m sure he’ll win again. The key is to improve on your weaknesses.”

The 41-year-old Englishman, a five-time world champion, is seeking a record seventh Masters title.

O’Sullivan will play either Neil Robertson or Ali Carter in the quarter-finals.

Last night, Sheffield-based Ding Junhui also opened his account with a 6-3 victory over Kyren Wilson, with breaks of 120, 65, 73, 65 and 50.

Today, John Higgins plays Mark Allen (1pm), and Stuart Bingham tackles Joe Perry (7pm).