Ian McCulloch boxed clever to pull off a huge shock with victory over Ronnie O'Sullivan at the Welsh Open in Newport today.
McCulloch beat the defending champion 5-1, although O'Sullivan seemed to be struggling with an injury.
The 'Rocket' wore a strap on his right wrist and missed several balls he could normally be expected to pot although the world number one refused to confirm he had sustained a fracture while boxing in the gym.
"It's just a little problem the doctors are looking into," he said. "It's just a bit sore. I did something years ago and it feels a bit achy.
"I struggled. I was put under pressure and didn't put Ian under any. You can't afford to miss easy balls and if you don't do the business you'll get punished.
"He made a couple of good clearances and it was tough out there for me. It's very disappointing to lose."
McCulloch, the world number 16 from Preston, had lost his five previous meetings with O'Sullivan but took advantage of the chances that came his way.
He fired in a 94 clearance to win the third frame and claim a 3-0 lead and secured the sixth for victory with a run of 72 after O'Sullivan ran out of position on 58.
"I didn't know Ronnie had a problem until I spoke to him at the interval but I don't think it would have made any difference," said McCulloch, a semi-finalist in last season's World Championship.
"You have to do what I did, which is clear up when he misses. I've played him several times but haven't often played well against him.
"But it's just one win. I won't get carried away unless I'm here for the final."
Paul Hunter, who has recently finished his latest spell of chemotherapy treatment for neuro endocrine tumours on the lining of his body, was beaten 5-3 by Anthony Hamilton.
Hunter has only won one match all season and although he produced breaks of 56 and 61 he was a long way off his best.
Stephen Hendry failed to take advantage of O'Sullivan's shock exit from the event when he was knocked out by Barry Hawkins in the second round.
O'Sullivan's loss gave Hendry a chance to extend his lead at the top of the provisional rankings but the Scot was beaten 5-3 by Kent-based Hawkins.
"It was a normal performance for me," said a downbeat Hendry, yet to win a title this season.
"It's a miracle I'm provisional number one. If I started to play well I'd go miles ahead but I got there by not playing well.
"It's the other players' fault that I'm top. Ronnie has thrown it away rather than me doing anything. I don't want to get to number one by only getting to quarter-finals.
"I wasn't thinking about Ronnie losing because I knew it would be a tough match against Barry."
Hendry was the victim of a refereeing error in the third frame when he was awarded four points rather than six when Hawkins fouled the pink.
The frame came down to a re-spotted black, which Hawkins potted to lead 2-1 and he pulled away to 4-1 with the help of a 128 break in the fifth.
Hendry's 133 total clearance reduced the gap to two frames and the seven-times world champion also won the seventh but Hawkins finished off in style with a well-crafted 86.
"I didn't fear Stephen after beating him in a long match," said Hawkins, who stands ninth in the provisional rankings.
"I'm getting more used to the TV conditions and I'm pleased with how I played overall. I got a bit shaky at 4-1 up but finished off well."
Another snooker legend, six-times world champion Steve Davis, suffered a shock exit when he was edged out 5-4 by 20-year-old Jamie Cope, who was making his television debut.
The Stoke potter did not betray any signs of nerves as he established a 2-0 lead with breaks of 94 and 92.
Davis fought back to lead 3-2, constructing a run of 131 in the fifth frame but despite also making it 4-4, Cope's 63 helped the newcomer clinch victory.
