But a break of 88 settled any nerves and O'Sullivan did not look back after snatching a scrappy third frame, with two further visits of 89 and 82 sealing a comfortable 5-1 win at the Wuhan Gymnasium.

The seven-time world champion could still be bumped off the top of the rankings if Mark Allen were to go all the way in the first ranking event to be held on Asian soil after four years off the calendar.

But O'Sullivan was happy to progress into the next round and had a kind word for Ding Junhui, who he could meet in the last 16, after playing on the table next to the long-time Chinese favourite.

"I played a lot with Ken when I was a kid, well I was a kid and he was an adult. I learned a lot from him," O'Sullivan said on World Snooker's official website.

"I call Ding the Godfather of snooker in China. He put snooker on the map here. He came along at an early age and was winning tournaments. He is a credit to himself, his family, and everyone in China.

"He is a great player and has been a constant of the game for 20 years, so Ding is a legend in China. To share the venue with Ding was nice. He got an amazing cheer which was nice to see."

Brecel's withdrawal from this event meant only an O'Sullivan slip-up would have seen the reigning world champion move to the rankings summit but Allen could still leapfrog the pair of them.

He was on the verge of an early exit against Mark Joyce but the Northern Irish potter, while far from fluent - he registered just one 50-plus break - won the last two frames to triumph 5-4.

Ding came back from 2-1 down to beat Ashley Hugill 5-3 while there were also wins for Stephen Maguire, Ali Carter, Robert Milkins, and Jack Lisowski but Marco Fu was an early casualty.