Joe Perry booked his place in the semi-finals of the World Championship after overcoming Stephen Maguire 13-12 in a titanic last-eight clash.

The evening session was a see-saw battle with 50-plus breaks in all but two of the frames and the lead changing hands frequently.

With nothing separating the players, the match went to a decider and Perry started with a break of 33.

Maguire then missed two chances and Perry sealed the win with a 54 break.

I played him last year and slaughtered him to be honest and I thought I was going to do it again Stephen Maguire

"I'm gradually fulfilling all my ambitions," said Perry, the world number 18. "When you turn pro you want to play at the Crucible, then reach the one-table stage, then reach the final and then win it. I am absolutely thrilled.

"I was just trying to keep my cool in the last frame. I was nervous, but I've been a lot more nervous than that before and I was surprised at how calm I was when my chance came along.

"There is no such thing as an easy draw but I knew I had a struggling Graeme Dott in the first round and then either Steve Davis or Stuart Bingham in the second. I knew if I could find some form anything could happen."

Maguire, a semi-finalist here last year, was one of the fancied tips to win his first Crucible title after securing the Northern Ireland Trophy and the China Open this season.

But he could not shake off the tenacious Perry who had led 8-7 after the opening two sessions.

"I never gave him the respect he deserves," said the 27-year-old from Glasgow - the only player to win two ranking events this season.

"I played him last year and slaughtered him to be honest and I thought I was going to do it again.

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"There was something missing, I don't know if I was mentally in that match. The final frame was the first bit of pressure I have been under and it was like 'Where did that come from?' I never handled it."

Perry opened up the final session by taking a healthy lead in the opening frame but Maguire fought back to draw level - a pattern which became the story of the evening.

In the next, Perry's 59 was eclipsed by Maguire's 70 as the Scot took a 9-8 lead only for the Englishman to level the match again with a 63.

Maguire received a slice of bad luck in the 19th frame, getting a massive kick when a big break seemed on the cards, and Perry constructed a well-made 55 to go in front once more.

Perry soon went behind however after letting commanding leads slip in the next two frames, Maguire taking advantage with breaks of 60 and 63 to go 11-10 ahead.

But Perry was not to be denied, and the 32-year-old Cambridgeshire player drew level with the help of a 54.

The 23rd frame descended into a safety battle when a black was left in the jaws of a pocket and after a re-rack, Maguire fired a 50 break only for Perry to hit back with what should have been a frame-winning break.

But when on 43, Perry missed the final yellow into the corner with the rest and Maguire nicked it on the pink.

Perry won a tense penultimate frame to take the match into a decider and he looked to have blown a wonderful chance when, on a break of 33, he amazingly missed the bunch of reds he was trying to split after potting the blue.

But Maguire failed to take advantage, rattling a red in the jaws of the bottom pocket and leaving Perry to compile his match-winning break.