Snooker: Stylish O'Sullivan stops Williams taking his cue

Ronnie O'Sullivan, snooker's unpredictable genius, who snatched victory from four down with five to play against Peter Ebdon in the quarter-finals, led Mark Williams 5-3 at the interval of their best-of-17 frames final of the UK Championship.

Williams, who beat Stephen Hendry from the same unlikely position, won the opening frame at York's Barbican Centre with an 86 break and the third with pink and black to lead 2-1. But O'Sullivan, who had taken the second with a run of 87, made 107 in the fourth to level at 2-2 and, from the Welshman's inadequate safety shot, went 3-2 ahead with a last red to pink clearance.

Williams, looking for his second UK title, potted only one ball in the sixth, and in the seventh a total clearance of 142 gave O'Sullivan a 5-2 lead and a chance at the £10,000 prize for the highest break in the televised phase.

Williams kept himself in contention by salvaging the last frame of the afternoon but had made more errors than could be afforded against a player of O'Sullivan's calibre.

Williams has admitted that he has been newly "fired up'' by various slights on his status as world No. 1, including his omission from the tournament's promotional literature and from BBC TV's much-shown promo.

His consistency over the last two completed seasons guarantees him the No 1 ranking until May, but it is 14 months since he won a title.

Three more finals and five semis since then, he remains pretty good by most standards but he was dreadfully jaded in the closing weeks of last season from incessant practice and matches, and had not fully recovered his appetite in the early stages of the current campaign.

Having sprained his ankle playing football, he hobbled painfully to October's LG Cup quarter-finals in his carpet slippers and showed more of his old drive in reaching the European Open semi-finals two weeks ago.

His capture of the European Open title, his first in a ranking event for 27 months, showed that, with the help of Terry Griffiths, he has repaired faults which had crept into his technique. But his old imperious clinching of winning positions has not returned.

Several match-clinching chances and three of the last five frames went unconverted against Williams. Ken Doherty suffered an even clearer attack of clincher's disease against Stephen Lee in Friday's semi-final before a fluke pink made him a 9-7 winner. He cannot win today without a more positive approach.