John Higgins fought back from 3-0 down to edge out Mark Williams in a seven-frame nail-biter in the last-16 of the Northern Ireland Open in Belfast.

In what was the 40th meeting between Higgins and Williams, who both joined the circuit in 1992, the Scot moved 21-19 in front in the head-to-head count.

"I was one ball away from losing at 3-0 behind. Mark will be kicking himself," Higgins said.

"Mark has beaten me the last few times we have played so it was good to get a little one back on him."

Welshman Williams had to don a slipper after he claimed a dietary switch to vegetarianism saw him suffer with gout.

The three-time world champion said ahead of that match that a bout of gout had left him unable to put a shoe on his left foot.

Williams said: "A couple of weeks before it happened, for no reason I stopped eating meat and went on a vegetarian diet for a couple of weeks – and then I got gout!

"I'm feeling much better now. I can almost walk like normal. I’m on these tablets for it now.

"I have a slipper on my left foot. I cannot get a shoe on it. It’s too painful. I brought it over with me to Northern Ireland."

Rocket Ronnie O'Sullivan crashes out after asking fans to 'sit down' at Northern Ireland Open

Judd Trump, winner of the last three Northern Ireland Opens, survived a scare to beat Jimmy Robertson 4-3.

Robertson had a chance to win the final-frame decider at the Waterfront Hall but a missed yellow cost him dear.

Trump told Eurosport: "I was 2-0 up again and I took my foot off the gas. The concentration isn’t quite there.

"I’m normally quite good that when I’ve got my man or woman on the ropes I put them away.

"But I’m not doing that at the moment and letting them back in the game way too easy. You get punished at this level and I nearly went out because of it."

Trump will face local favourite Mark Allen next, the Northern Irishman booking his quarter-final place with a 4-3 victory over Stephen Maguire.

In the late matches, David Gilbert stunned world number one Mark Selby 4-2, while Ricky Walden overcame a tough fight from Jackson Page to win 4-3.