LONDON, April 26 (Xinhua) -- World number one Ronnie O'Sullivan has joined Peter Ebdon, Marco Fu and Graeme Dott in the semi-finals of the world championship after beating Mark Williams Wednesday in Sheffield, England.

    Defending champion Shaun Murphy missed out on a place in the last four, suffering a 13-7 defeat at the hands of England's Ebdon.

    Fu from Hong Kong, China, became only the second Asian player to reach the semi-finals 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.

    O'Sullivan survived a late challenge from Williams, twice the world champion, as the Welshman fought back strongly from 10-6 down to level at 11-11 before losing the game 13-11.

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