Liang Wenbo became the first Chinese player to reach the quarter-finals at The Crucible as he won 13-12 in an enthralling match over Joe Swail.

Swail fought back from 12-8 behind to force a deciding frame, but a missed brown with the rest allowed Liang, 21, to clinch a classic encounter.

Liang celebrated prematurely in the 23rd, thinking he had won the match.

But Swail pinched the frame to keep the match alive and continue his fightback, only to fall at the final hurdle.

Liang, who will face tournament favourite Ronnie O'Sullivan in the next round, punched the air with delight after potting the blue to go 59-44 ahead in the 23rd frame, with only pink and black remaining.

But he went on to miss a difficult pink and Swail snookered him and went on to win the frame and close to just one frame behind.

A break of 66 eventually proved enough to make it 12-12 and set up what must go down as the most thrilling frame of the tournament so far.

Both players had chance after chance in a desperately tense atmosphere.

Liang led by 27 points with only 27 left on the table, only to again fail to get out of a snooker by playing cushion first.

He hit the yellow direct at the second time of asking, but Swail was clearly unhappy at the way the balls had been replaced.

606: DEBATE It was one of the most engrossing matches I've ever witnessed at The Crucible. An outstanding advert for snooker Qoxiivi

"It's very, very hard to take," Swail said. "There was absolutely no way he could see the yellow. If that was the case why not play that shot in the first place?

"I'm absolutely fuming at that. I think it was a very unprofessional thing to do and I told him (Liang) that. I will have to look at it again but I'm 99% sure he could not see the yellow.

"Any player would be honest enough to say I can't see the yellow. When I put him back in I was taking it for granted he would come off the side cushion again."

Swail was asked to agree that he was happy with the placement at the time, but admitted: "When you are out there you are all scrambled."

But Liang insisted he had not tried to gain an unfair advantage.

"I could see the yellow but it was so thin I was worried the ball could go in-off so that's why I played off the cushion the first time," he said.

Liang went on to knock the green in when attempting to pot the yellow, but Swail missed a simple brown with the rest and the Chinese youngster finally sealed a remarkable victory.

"I am delighted to make the quarter-finals and I am looking forward to playing O'Sullivan," he added.

"In the last frame I had calmed down a bit because there was nothing to lose but before then I was very tense."

Earlier, world number 18 Joe Perry moved into the last eight after sealing a 13-9 win over fellow qualifier Stuart Bingham. Bingham took two of the opening three frames - with a 137 in the 19th the highlight - to close to 10-9 behind.

But Perry refused to be intimidated as he took the next comfortably.

Perry has not been in the last eight in Sheffield since 2004

A break of 69 took Perry to the brink of victory and a missed red by Bingham in the last let his opponent clinch the frame and match on the black.

It was the first time Perry has reached the last eight at The Crucible since 2004.

"It's been a while but I'm very happy to be back," said Perry, who will face Stephen Maguire in the next round.

"The first session was a non-event for me but I improved after that and stood up to the pressure and played some good stuff.

"It's the biggest tournament we play, it's every player's dream to lift the trophy and I'm no exception. The dream is still alive."

Perry added: "It does not come much tougher than playing Stephen in the next round but this is the World Championship and to be the best you have to beat the best.

"We've had a few tight tussles and he gave me a whipping here a couple of years ago but I think I'm a better player now than I was then."