The Scot fluked a treble on a respotted black in the deciding frame to set up a clash with Stephen Lee, who beat reigning champion Judd Trump 5-3.

Maguire, winner in Beijing in 2008, opened a 2-0 lead before three-time world champion O'Sullivan hit breaks of 88 and 60 to level.

O'Sullivan responded again at 3-2 behind with a brilliant clearance of 102, which he capped by blasting in the final black.

Maguire moved within a frame of victory and looked to be on his way to the final four in the eighth, only to overstretch on a black and give O'Sullivan the chance to force a decider.

O'Sullivan appeared in control before letting Maguire in to clear the colours and tie the frame, giving him the chance to make his fluke count for plenty.

Lee made it four semi-final appearances in five ranking events with his triumph over Trump, who failed to make the most of taking a 2-0 lead.