Ronnie O'Sullivan edged past Xiao Guodong 6-4 in their first-round match at the International Championship in Daqing, but Ireland's Ken Doherty failed to make the last 32.

An opening century break of 137 helped five-time world champion O'Sullivan move into a 3-1 lead.

However, Chinese player Xiao rallied to level the best-of-11 contest with breaks of 69 and 79 before O'Sullivan restored his advantage at 5-3.

Xiao took frame nine with a break of 54 but then missed chances to force a decider as O'Sullivan, currently ranked number nine in the world, tied the next to force a re-spotted black before his Chinese opponent went in-off to hand the Englishman victory.

Doherty, winner at the Crucible in 1997, was well beaten 6-3 by England's Ricky Walden.

The Dubliner fell 5-1 behind in a scrappy encounter as Walden cobbled together three half centuries. Doherty raised hopes of a comeback by hitting form with breaks of 69 and a superb 133 - the only century of the match - but Walden closed out victory with a classy 75 in the ninth frame.

Welshman Mark Williams, world champion in both 2000 and 2003, lost the last two frames in a 6-5 defeat by wildcard Xu Si.

Other players to reach the last 32 included world number one Mark Selby, Judd Trump, Shanghai Masters champion Ding Junhui and John Higgins.

Selby beat Alfie Burden 6-2, while Higgins defeated Eden Sharav 6-3. Ding saw off David Grace 6-1 and Trump, the world number three, beat amateur wildcard Yuan Sijun 6-3 while world number two Stuart Bingham was a 6-1 winner over Zhang Jiankang.