Defending champion Peter Ebdon bowed out of the Maplin UK Championship with a dramatic 9-8 first-round defeat by Ian McCulloch in Telford.
Ebdon's title defence fell at the first hurdle
McCulloch trailed 5-0 at one point but battled back to lead 8-7 before Ebdon forced a deciding frame.
Former winner Ding Junhui safely advanced to the last 16 with a 9-3 win over the local boy Adrian Gunnell.
But Steve Davis, who lost to Ding in the 2005 final, is out after a 9-4 defeat by Stuart Bingham.
Dubai-based Ebdon looked well in control of his match during Saturday's opening session but McCulloch held his nerve to secure the victory with a break of 84 in the final frame on Sunday.
"You struggle to come back from 5-0 down against the kids in the club these days, let alone someone like Peter," said McCulloch.
"Even had I lost 9-8 I could have taken so many good things from this match.
"A lot of it is down to how you prepare. I've always been one to practice with players who cut your throat!
"None of them are slap-dash merchants and that really helps when you need to fight."
Ebdon flies back to the Middle East wondering how the match got away from him.
"When Ian got it back to 5-3 at the end of the first session I knew then I was in for a tough fight," he said.
"I didn't do a lot wrong but Ian was exceptional at times. My concentration was good but I just wasn't as sharp as I should have been.
"It's very tough coming to the UK to practice for tournaments. I am a family man and it can be a lonely existence but that's my job."
Former world champion Shaun Murphy is also through to the last 16 after he fought off a strong challenge from Cardiff-based qualifier Paul Davies.
The 2005 Crucible champion led 4-1, saw the Welshman fight back to 4-4, but raised his game to grab a deserved 9-5 victory.