Anthony McGill described beating Ronnie O’Sullivan at the Crucible as his best ever career win so far.

The Scot fought back and held his nerve from 12-11 down to make breaks of 136 and then 85 in a final frame decider to knock out the defending champion in the second round of the World Championship.

The match was undoubtedly the best of the tournament so far.

McGill, who sensationally lost out in the World Championship semi-finals last year, will play either Stuart Bingham or Jamie Jones in the quarter-finals.

The world number 16 looked to be in control when he led 10-6 after a brilliant second session which saw him win six frames out of eight against the world number 2.

But O’Sullivan came storming out the blocks quickly in the deciding evening session and managed to wipe out McGill’s lead and level at 10-10 before taking the lead.

McGill managed to stop the rot and get a crucial frame on the board to level at 11-11 but O’Sullivan responded well to move within a single frame of victory.

However, McGill showed brilliant determination making a superb break of 136 to keep his chances alive before making a match-winning break of 85 under the most intense pressure.

After the match McGill said: “I was making mistakes and couldn’t get any rhythm going. I managed to turn it on in the end. It’s the best win of my career, no doubt about it.

“A few years ago I thought I was rubbish, but now I believe in myself to at least play well.

“I was calm in the last frame, I had it in my mind that it wasn’t the last frame and we were going to play all night.

“I wanted to play all night, it was just so good! It only hit me when I potted the last red that we were in a decider. Ronnie said to me at the end that I had played well and deserved it. The semi-final from last year didn’t cross my mind at all – that’s gone.”