O'Brien wins Irish battle

O'Brien - who will face Barry Hawkins in the semi-finals - admitted the turning point came when he took the third frame with a composed 59 clearance after finding himself 58-0 down.

O'Brien added: 'I won a deadly third frame. I felt a bit of pressure in the last frame because you know with Ken he never gives up, so to get over the winning line is important.

"It was a great atmosphere out there. We both knew before that there was going to be one Irishman in the semis, I'm just glad it's me. I'd be foolish to say I'm going to win the tournament, I've got a tough match and if I play well there's every chance I can get into the final.'

In the second quarter-final John Higgins survived a fightback before clinching a 5-4 victory over world champion Graeme Dott.

Higgnes made two centuries to move in to a 4-1 lead before Dott battled to level matters with runs of 85 and 64, although Higgins took the decider 83-41 points to set up a last four clash against either Ronnie O'Sullivan.

O'Sullivan and Northern Ireland's Joe Swail were level on four frames apiece but the Londoner sealed victory with a maximum 147 break, while Hawkins is also through to the semis after defeating Stephen Hendry 5-2.