World number one Mark Selby last night produced a superb fightback to book his place in the quarter-finals of the Betfair Masters at the expense of Stuart Bingham.

Selby trailed 5-1 at Alexandra Palace but reeled off five frames in a row to win 6-5 and set up a last-eight clash with former world champion Mark Williams.

After Selby took the opening frame with a break of 63, Bingham assumed command of the match as runs of 55, 78 and 86 took him 4-1 in front.

The Basildon right-hander then came out on top in a protracted safety battle on the colours in the next to move within one frame of victory.

However, Selby belatedly began to find some form and breaks of 57, 86 and 68 got him back on level terms as Bingham started to feel the pressure.

Bingham was first in after an excellent opening red in the decider, but badly missed a blue into the top corner to let Selby in.

And although he needed three chances, the Leicester cueman eventually wrapped up an unlikely victory and celebrated with a clenched-fist salute towards friends and family in the crowd.

In the afternoon session, Williams admitted he had dragged opponent Matthew Stevens down to his level before claiming a scrappy 6-4 triumph.

Williams was completely out of sorts as he trailed 4-1 and saw Stevens on the verge of winning the sixth frame as well.

But Stevens missed a simple brown to go 5-1 in front and from then on committed numerous basic errors as Williams took five frames in a row to secure an unlikely win.

"I didn't play very well at all, to be honest. Neither did Matthew," Williams told BBC2.

"He missed a sitter of a brown for 5-1 and I don't think I'd have come back from 5-1 to be honest.

"Even though I wasn't playing too well I was still trying 100 per cent, and perhaps that's got what me through in the end.

"It's easy to win when you are playing well, but it's hard when you're not playing too well and I was getting hammered out there really. I'm over the moon that I just stuck in there, tried my best and managed to turn it around somehow.

"Matthew helped me out a lot. He missed a lot of balls he normally wouldn't miss. Perhaps I dragged him down a bit and pounced on him.

"Coming into this tournament I practised really hard and was probably playing the best I have for years and years, knocking 147s in every single day near enough.

"I was quite confident coming up here and then I go out there I can't make 47. If I can bring the practice to the match table I've got a chance, but I just can't do it at the minute. I might be trying too hard."

Former world championship finalist Stevens looked in complete command of a low-quality match when he led 4-1 and made a break of 59 in the sixth frame.

Williams made 37 to get back into the frame before missing a straight yellow, but Stevens then missed an equally easy frame-ball brown to let his fellow Welshman off the hook.

The left-hander improved from then on and runs of 59 and 68 helped him into a 5-4 lead, while he sealed victory with breaks of 48 and 44 after Stevens had missed a black off the spot.