Stephen Maguire edged Ronnie O'Sullivan out of the Masters with a thrilling 6-5 first-round win after an astonishing last-gasp reprieve at Wembley Arena.
O'Sullivan and Maguire shake hands after a compelling match
In the deciding frame, O'Sullivan missed a key blue with the rest to let the Scot steal it at the death.
The enthralling match saw Maguire open up a 3-1 lead at the interval with breaks of 103 and 84.
O'Sullivan, who beat Maguire 10-2 in the UK Championship final, levelled at 5-5 before the dramatic finale.
The match pitted provisional world number one O'Sullivan against the provisional world number two, and it lived up to expectations with some nail-biting moments and high-quality shots.
I had my chance and I didn't take it
Maguire made a strong start, and a miraculous escape from a horrible snooker helped him to take the opener before O'Sullivan levelled with a 68 in the next.
Breaks of 103 and 84 took Maguire 3-1 ahead, and he went further clear by winning the scrappy fifth frame but he seemed less assured after the break.
O'Sullivan showed his class with runs of 103 and 72 before Maguire stopped the rot with another frame.
More pressure came Maguire's way as the defending champion made runs of 66 and 64 to force a decider, but O'Sullivan failed to make a winning position count with the crucial missed blue.
O'Sullivan was philosophical about the result, saying he would quickly forget about the match.
"I had my chance and I didn't take it," said O'Sullivan.
"If you don't take your chances then don't expect another one.
"You just have to put these results behind you. In 10 years' time will this match have much significance in what I've done in my career? I don't think so."
Maguire said he had resigned himself to defeat in the final frame.
I was actually thinking 'what am I going to do tonight now that I'm out?'
"At 4-1 up I was feeling brilliant and I felt as though I didn't fancy missing if I split the pack, I was confident I could clear up at one visit," he said.
"But he's made a 100 break to come back to 4-2 and I was thinking 'what have I got to do to beat this guy?'
"I was never in doubt he was going to clear up. I was 100% sure he was going to clear up.
"I was actually thinking 'what am I going to do tonight now that I'm out?'"
Earlier, former world champion Shaun Murphy shrugged off a slow start to seal a 6-3 win over Ali Carter in the opening match of the tournament.
Carter took the opening two frames before a break of 66 in the third got Murphy into the swing of things.
Murphy was not at his best in the opening match
Murphy levelled the scoreline, but a 77 edged Carter back in front.
But with neither player finding top gear, Murphy proved better at grinding out the remaining frames as Carter's frustration got the better of him.
Murphy admitted he had not hit his best form, but said he had been short of practice time because of illness.
"I'm very pleased about my game considering I had not practised over Christmas because I was ill," said Murphy.
"I was going to the toilet every 20 minutes. I'm still not well and Ali was poorly during the match too."
In the final match of the day, Wales' Ryan Day provided the quality in a low-key wildcard round victory over a misfiring Barry Hawkins.
Day raced into a 3-0 lead as Hawkins spurned a series of opportunities, although the Englishman did pull one frame back before the interval.
The fifth frame saw Day in with a chance of a 147 maximum break, but he broke down on 113.
Hawkins took a scrappy sixth, but that was as good as it got as Day made breaks of 55 and 120 to seal a 6-2 win.