Ronnie O'Sullivan, winner of the World Championship at the end of last season and the Northern Ireland Trophy at the start of this, continued his pursuit of a third consecutive ranking title, a feat previously achieved only by Ray Reardon, Steve Davis and Stephen Hendry, by beating Mark Williams 5-3 to reach tomorrow's semi-finals of the Shanghai Masters. His opponent will be Stephen Maguire, the world No3, who was a 5-4 winner over Ryan Day in his quarter-final.

O'Sullivan' s commanding performance included breaks of 93, 87, 100, 106 and 78 and only one major blemish, a careless pink on 53 in the fifth frame which let Williams in for a 55 clearance. Williams, twice world champion and world No1 only five years ago, also made a break of 128 in the penultimate frame.

Ricky Walden, the world No35 from Flint, dropped the first two frames to Davis but finished an impressive 5-2 winner, clearing with 58 to snatch the sixth frame on the black and adding a 139 total clearance to clinch his place in a ranking semi-final for the first time. His opponent today will be Mark Selby, the Masters champion, who from 3-1 down and 48 behind in the fifth beat Marco Fu 5-3.