World number 37 Stuart Bingham shocked Steve Davis 6-4 to reach the second round of the Masters at Wembley.
In a tight game, Bingham secured the win with a break of 54 in the final frame and will next face Peter Ebdon.
Mark Williams proved too good for three-time winner Paul Hunter, beating him 6-3 in Hunter's first Wembley match since being diagnosed with cancer.
The last match of the evening went on until near midnight, before Ian McCulloch beat Joe Perry 6-3.
Davis' defeat by Bingham was a bitter blow after his career seemed to be revived following his final appearance at last month's UK Championship.
"I suppose I'm disappointed, but I'm philosophical about winning and losing these days," he said.
"It was a scrappy old game and neither of us deserved to win it. The game never got off the ground."
"It was a day of hard grafting and mentally. Perhaps I was not up for as I should have been."
In the second round match, Williams led 2-0 before Hunter hit back to win the next three frames, a run of 59 in the fourth frame his best score at the table.
But the Welshman controlled matters after that to set up a meeting with either seven-times world champion Stephen Hendry or Glasgow's Alan McManus.
Williams admitted it had been a strange experience playing against close friend Hunter, knowing how ill he is.
"It's a strange experience playing him when you know he's not at his best, especially because he's a good mate," he said.
"It's amazing Paul is out there doing as well as he is. I get on really well with him and wish him all the best."