Defending champion and seven-time winner Ronnie O’Sullivan is out of the Masters after a magnificent 6-1 quarter-final victory for Mark Allen at Alexandra Palace.

O’Sullivan won the first frame with a break of 75, despite calling a foul on himself as he cued over a red to attempt a difficult black.

But that was as good as it got for the five-time world champion as Allen responded to take the second frame with a break of 65.

Mark Allen lines up a shot during his Masters quarter-final with Ronnie O'Sullivan
Mark Allen claimed a notable 6-1 victory over Ronnie O’Sullivan at Alexandra Palace (John Walton/PA Wire)

That was followed by breaks of 115, 85 and 81, which gave Allen a 4-1 lead.

And breaks of 39 and 21 helped him to within one frame of victory.

Both players missed chances to take control of the seventh frame, before Allen grasped his opportunity to claim a notable scalp and his place in the semi-finals of the tournament which concludes on Sunday.

O’Sullivan, who has been struggling with illness, told BBC 2: “He deserved his win, it was one of those things, good luck to Mark.

“From my perspective I can rest up now and get ready for my next event. I had to show up, if I was a football player I would have missed this game.

“I’m struggling, I don’t know if it’s a virus, I’ve had it before and it’s very difficult, I gave it a go.”