Ronnie O’Sullivan crashed out of the Northern Ireland Open after urging fans to “sit down” midway through his 4-3 defeat to Masters Champion Yan Bingtao.

It capped a fractious week for O’Sullivan at the Waterfront Hall, having criticised the lack of atmosphere at the venue before feeling the need to clarify that his complaint had not been aimed at fans.

However, O’Sullivan’s frustration got the better of him during the third frame against the Chinese when he paused midway through a break of 129 to urge fans to keep to their seats.

His complaint prompted the referee to instruct stewards not to let fans enter the auditorium mid-frame during the best-of-seven match.

The 21-year-old Yan nudged in front for the first time at 3-2 but O’Sullivan hit back from the brink when he erased a 71-point deficit in the following frame to take the match into a decider.

Both players had their chances to claim victory and ultimately it was two costly errors from O’Sullivan that ended his hopes of returning to the final for a fourth straight year.

John Higgins fought back from 3-0 down to edge out Mark Williams in a seven-frame nail-biter.

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.”

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

Betfred World Snooker Championships 2021 – Day 10 – The Crucible
Reigning champion Judd Trump won a seventh frame decider to make the last eight in Belfast (George Wood/PA)

Robertson had a chance to win the final-frame decider 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.