SNOOKER/World Championship: Ken Doherty bowed out of the World Championship yesterday with an admission that he might have only three more years to realise his dream of lifting snooker's ultimate prize for a second time.

Given the form which the Dubliner took into the tournament, and the draw he had, it seems unlikely that those three years will present him with a better chance than this.

Doherty was beaten 13-10 by Marco Fu from Hong Kong, who is now through to the semi-finals here for the first time in eight years as a professional.

Resuming at 8-8, Doherty won the first frame of the day from a single chance with a break of 74, only to lose the next to a total clearance of 135 as Fu's third century of the match got him back on terms at 9-9.

Fu, the world number 24, looked certain to go in front when he ran 67 to leave Doherty needing three snookers in the next.

Remarkably, the Irishman ended up pinching it on the black for what looked to be an important 10-9 lead, but it proved to be the last frame he won.

After winning frame 20 on the pink to draw level once again, Fu took control of the next frame with a break of 60.

Doherty had a great chance to steal it but came up short with a slow roll on the brown to a middle pocket, and Fu stepped in to take the opportunity and secure a 11-10 lead.

The 22nd frame followed a similar pattern as Fu made another 60, and Doherty had another chance to come from behind and take it.

Again he missed at a crucial stage though, this time on the blue after playing a poor positional shot in potting the last red.

That effectively handed the frame to Fu, and he needed only one chance in the next, stroking in a long red to launch the 75 break which made him only the second Asian player ever to reach a world semi-final.

"I blew it and I can't grumble about it" admitted an honest Doherty after his defeat.

"I lost some silly frames and should have been a few in front instead of being a few behind. It was that brown and then the blue which did for me in those frames. When you lose frames like that, you put yourself under real pressure, because it means more out there than it does in any other tournament."

With his 37th birthday coming up in September, Doherty acknowledged time is running out for him to repeat the famous triumph he enjoyed here in 1997.

"I've always said that you're unlikely to win it once you hit 40, so I've probably only got three more years to do it again."

Fu said his return to form had been brought about by a decision last year to start working with 1979 champion Terry Griffiths, now the game's most prominent coach. "I didn't come here looking to win the event. My only goal was to enjoy my snooker again, because I haven't been doing that for the last year or two," said the 28 year-old.

Peter Ebdon will now play Fu in the semi finals, after beating last year's winner Shaun Murphy 13-7. Murphy's defeat means 10 years have now passed since Stephen Hendry became the last player to retain the world title.

Scotland's Graeme Dott, who reached the final here two years ago, held on in the face of an admirable recovery from Australian Neil Robertson to move into the last four.

From 12-8 down, Robertson won the next four frames, before Dott held his nerve to come through in a tense decider, 13-12.

Meanwhile, Ronnie O'Sullivan held off a late fightback from Mark Williams to record a 13-11 win and setup a last four clash with Dott.