SHEFFIELD (England), April 26: Scotland's Graeme Dott held off a late surge from Australia's Neil Robertson to book his place in the semifinals of the World Snooker Championship with a dramatic 13-12 win at The Crucible on Wednesday.

Dott came through in the best of the 25 frames quarterfinal despite a wobble in the final session.

Resuming 10-6 ahead, Dott looked to be coasting to victory as he established a 12-8 lead before Robertson came back to win four frames in a row – including breaks of 74 and 103 – to force a winner-takes-all 25th frame.

Robertson started the session with a 53 break to take the opener, and followed it up with a 106 in the 18th frame.

But the 17th and 19th frames went to Dott to give him a comfortable 12-8 lead at the interval.

Robertson made a 74 break to cut the gap to three frames.

Dott should have sealed the match in the next frame, but missed a straightforward red.

The Australian made a 103 in the 23rd frame, after Dott had been forced to play into the reds when the referee replaced the white in the wrong place, and then took the next to force a deciding frame.

Both players had their chances in the decider but Dott held firm for victory.

Meanwhile, reigning champion Shaun Murphy is playing catch-up after succumbing to the red hot cue of Peter Ebdon.

Murphy, aiming to become the only first-time champion to successfully defend the crown, had the local crowd behind him but that proved little help as Ebdon raced to a 10-6 lead.

There was some disappointment for Ebdon, the 2002 champion who is now based in Dubai, after he missed the chance of a maximum 147 break in frame seven on Tuesday.

After potting 12 reds and 12 blacks, the 35-year-old left himself a tricky pot into the middle, bridging over another ball, and agonisingly saw it hit the jaw of the pocket.

Ken Doherty however is having a tougher time against Marco Fu of Honk Kong, who followed up a break of 121 in frame seven with a session-ending break of 110 which tied the match at 8-8.

Former double champion Ronnie O'Sullivan meanwhile finished his first sessions against Mark Williams tied 4-4, although the Englishman was in hot water for a mumbled obscenity after a fluffed shot.

After the opening two frames had been shared, each player making a single visit to the table count, 'The Rocket' vented his frustration in the next.

A poor positional shot prompted an audible obscenity from the world number one, earning him snooker's equivalent of the yellow card.

Latest results and scores on Wednesday:

Quarterfinals (best of 25 frames): Graeme Dott (Scotland) beat 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); Peter Ebdon (England) leads Shaun Murphy (England) 10-6 (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); Mark Williams (Wales) is level with Ronnie O'Sullivan (England) 4-4 (0-90, 94-0, 64-56, 68-0, 2-60, 73-4, 11-85, 19-89); Ken Doherty (Ireland) is level with Marco Fu (Hong Kong) 8-8 (83-38, 94-0, 32-91, 28-85, 53-62, 63-71, 1-126, 69-1, 12-102, 89-18, 80-40, 104-28, 68-45, 61-50, 14-86, 0-134).—Agencies