Ronnie O'Sullivan and Ken Doherty are hoping to avoid a China crisis

Former champions Ronnie O'Sullivan and Ken Doherty were having to ward off the Chinese invasion as they entered the fray at snooker's world championship today.

O'Sullivan, bidding for his third title, faced 17-year-old Liu Chuang, while Doherty soon found himself in trouble against qualifier Liang Wenbo.

Doherty won the opening frame but Liang showed no sign of nerves on his Sheffield debut and took the next three with breaks of 40, 77 and 58.

China's Ding Junhui is already into round two after edging out Hong Kong's Marco Fu 10-9 to set up a clash with seven-times champion Stephen Hendry.

Former UK champion Ding led 5-1 before Fu won six of the next seven frames.

Ding went back in front with efforts of 97 and 114 but Fu forced a decider, which Ding won with a break of 76.