LONDON - China's hopeful Yan Bingtao was edged out of the World Snooker Championship after losing to veteran Mark Williams 13-11 in a close quarterfinal on Wednesday.

22-year-old Yan had ousted defending champion Mark Selby 13-10 on Saturday to reach the quarterfinals at the World Championship for the first time.

Yan showed his ability in a tough contest as he came from 6-2 behind to tie with three-time world champion Williams after two sessions on Tuesday, but failed to hold off the in-form veteran in the last session on Wednesday.

"I'm over the moon because I thought it was going to be another close game that went against me," said 47-year-old Williams, who became the oldest player to reach the semifinals at the World Championship for 37 years.

"I've had a lot of close games all year and lost them all. I did not feel under pressure at all, I just tried to get some momentum going," he added.

Yan, who beat veteran John Higgins in last year's Masters final, admitted that he was nervous because he was so close to his first semifinal appearance at the Crucible Theatre.

"At 11-10 I had a chance to make it 12-10, but I was thinking too much and lost the cue ball," he said. "Yesterday morning I lost my concentration and went 6-2 behind, then brought it back to 8-8 in the evening session. I believe in myself, I can do anything."

Williams will face Judd Trump next, as the 2019 world champion came from 8-5 down to defeat Stuart Bingham 13-8 with an eight-frame winning streak.

The other semifinal will see Ronnie O'Sullivan play against John Higgins. Both are 46 years old and have a total of 10 world titles between them.

Six-time world champion O'Sullivan swept Stephen Maguire 13-5 to reach to a record 13th semifinal in the year-ending tournament, while Higgins needed to fight until the decider to edge Jack Lisowski 13-12.