Ronnie O'Sullivan survived a stern test of his UK Championship credentials to beat Robert Milkins 6-5.
Milkins fought back from 4-2 and 5-3 down to force a deciding frame but missed a simple pink early on and then a delicate red to the centre pocket, and the latter turned the match back in O'Sullivan's favour.
O'Sullivan came back to the table trailing 24-0 and faced with a thin red he elected to play left-handed, finding the pocket to trigger a run of 46 which ended with a rare loss of cue-ball control.
That mistake eventually resulted in a third chance for Milkins, but another poor miss proved his final contribution as O'Sullivan hauled himself over the line at last.
O'Sullivan was 2-0 down early on but then ran off four frames in succession either side of the interval, registering the joint-highest break of the TV stages along the way with a 142 clearance.
The 83 break he produced in frame eight left Milkins needing all four remaining frames and he threatened to do it, a century of his own triggering what might've been a miraculous comeback had he held his nerve at 5-5.
But while Milkins couldn't make the most of three bites of the cherry, O'Sullivan took two and it was finally enough.
“I don’t understand how this game works,” shrugged O’Sullivan. “I gave up a long time ago. I just keep turning up and stinking out gaffs. I stunk it out today and I’ll stink it out tomorrow. You’ll have to get a mask to watch me play.
“I just don’t want it bad enough any more. I’m having to dig deep. When I was younger I didn’t have to dig deep, I was so hungry, and now I’m just thinking I don’t really care.
“It’s nice if I get through but I don’t actually want to work that hard. That’s why I like doing my exhibitions, my own shows in China. It’s still competitive but it doesn’t matter if you win or lose, you can have a drink after and a bite to eat.
“Competitive sport is hard, it’s not just about how good you are but how much you want it. I still want to play, I still like the lifestyle and the travelling. But I’m not going to kill myself out there, it’s not worth it.”
Next for O'Sullivan is a quarter-final meeting with Zhou Yuelong, who was a 6-3 winner against his idol growing up, John Higgins.
Zhou had already accounted for Neil Robertson and exuded poise when his chance came in frame nine, picking apart the necessary reds with only the pink to work with.
Zhang Anda continued his remarkable surge to prominence as he beat world champion Luca Brecel 6-4 with breaks of 124 and 68 in the final two frames.
Zhang, the sport’s in-form player who has won the International Championship and reached the English Open final in recent months, will next face Iran’s Hossein Vafaei, who fired three centuries and a further break of 94 in a 6-1 thrashing of Matt Selt.
Thursday November 30
Afternoon session (1300 GMT)
Evening session (1900 GMT)