SHEFFIELD (England), April 27: World number one Ronnie O'Sullivan secured his place in the semifinals of the world snooker championship after beating Mark Williams 13-11 on Wednesday.

Defending champion Shaun Murphy missed out on a place in the last four, however, when he suffered a 13-7 defeat at the hands of Peter Ebdon.

O'Sullivan acknowledged he had been pushed all the way by Williams after the Welshman, twice the world champion, came back from 10-6 down to level at 11-11.

“I didn't expect to win because he put so much pressure on me and looked so comfortable,” O'Sullivan said in the post-match press conference.

“He's a class act and there's a big mutual respect there, so it was a shame there had to be a loser. Playing the way I did was a great confidence-booster.”

Williams backed O'Sullivan to win the title for a third time.

“I think I've lost to the winner of the competition,” said Williams. “I can't see anyone beating him.”

Ebdon, who resumed with a 10-6 lead going into the final session, ended Murphy's reign by taking three out of the opening four frames.

The 35-year-old Englishman, who is now based in Dubai, believes he can reclaim the title he won four years ago after working hard in the build-up to the tournament.

“I believe I deserve it because I've worked hard and hopefully I'm coming into form at the right time,” Ebdon told reporters.

Ebdon paid tribute to the way Murphy has conducted himself since winning the title 12 months ago.

“He's been an outstanding world champion and I really appreciate everything he's done for snooker over the past year,”

Ebdon told reporters.

A dejected Murphy said: “Last year I potted everybody off the table, but I've not scored all the way through the tournament.”

Hong Kong's Marco Fu became only the second Asian player to reach the semifinals at The Crucible, following in the footsteps of James Wattana, when he beat Irishman Ken Doherty 13-10.

Scotland's Graeme Dott beat Australian qualifier Neil Robertson 13-12 to book his place in the last four.

Wednesday’s results:

Quarterfinals (best of 25 frames): Peter Ebdon (England) bt Shaun Murphy (England) 13-7 (116-11, 101-25, 58-44, 76-8, 65-60, 71-26, 96-0, 1-75, 74-0, 29-77, 29-68, 4-83, 90-12, 1-83, 0-131, 65-6, 112-0, 86-0, 17-48, 79-28); Graeme Dott (Scotland) bt Neil Robertson (Australia) 13-12 (53-78, 58-53, 77-4, 76-45, 73-15, 8-73, 4-132, 69-39, 87-4, 64-48, 90-32, 12-70, 82-5, 58-72, 68-62, 7-64, 0-68, 60-10, 0-106, 72-33, 1-74, 56-67, 0-111, 14-63, 60-48); Ronnie O'Sullivan (England) bt Mark Williams (Wales) 13-11 (90-0, 0-94, 56-64, 0- 68, 60-2, 4-73, 85-11, 89-19, 70-42, 72-1, 68-12, 0-77, 109-8, 4-116, 95-0, 85-1, 55-65, 4-63, 66-59, 11-67, 8-85, 17-58, 90-37, 62-18); Marco Fu (Hong Kong) bt Ken Doherty (Ireland) 13-10 (38-83, 0-94, 91-32, 85-28, 62-53, 71-63, 126-1, 1-69, 102-12, 18-89, 40-80, 28-104, 45-68, 50-61, 86-14, 134-0, 9-79, 135-0, 67-79, 68-57, 75-40, 67-30, 75-4).—Reuters