World No 22 Mark Williams ended his hoodoo against Ronnie O’Sullivan with a thrilling 6-5 victory to reach the International Championship semi-finals.
The Welsh potter was trailing 3-0 but ran in five frames on the trot - including notching a 120 break - to move within a frame of victory.
But back came The Rocket, who hit a 77 break as he took the next two to force the decider, with Williams holding his nerve to win through.
It was Williams’ first victory over O’Sullivan in a ranking event since the 2002 Thailand Masters – a run of eight ranking matches in a dozen years.
The relieved 39-year-old told World Snooker’s official website: “I haven't beaten him for so long, eventually I've got rid of that pain tonight.
"I was shocking for the first few frames today and dragged Ronnie down. After the interval I was a different player. I made some good breaks and I'm over the moon to get through.
"It's an excellent win for me, even though Ronnie wasn't at his best. We're both the same age but he can produce a lot better snooker than the likes of me and John Higgins. He's still the best player in the world."
O’Sullivan was gracious in defeat, saying: “We both started poorly and I was struggling with my concentration. Then he played well to go 5-3. He's in good touch.
“At 5-3 I felt I had to make something happen, and that was the best I felt in the match."
Williams will next face Mark Allen in the last four on Saturday after he also won five frames on the trot to come from 3-1 down to beat Michael White, notching breaks of 84, 76, 58 and 58 in that run.
The other semi-final will be contested on Friday by Robert Milkins and Ricky Walden after Milkins edged Marco Fu 6-5, while Walden easily defeated Jamie Burnett 6-1.