Peter Ebdon beat defending champion Ding Junhui 9-5 to secure a Maplin UK Championship semi-final against two-time former champion John Higgins.
Ding was playing for the ninth day out of 10 after starring at the Asian Games in Qatar.
The 19-year-old was unable to produce his best snooker and trailed 6-2 after the first session.
He battled back to trail 6-5 but Ebdon won the 12th frame on a respotted black and it was one-way traffic after that.
"This is a massive win for me," said Ebdon. "I've been working very hard for this tournament.
"I've been saying for four years just how special a player Ding is.
"The schedule he has had over the last couple of weeks is incredible.
"He has done brilliantly well and I'm just so pleased to win because I've practised so much against him and I know what he's capable of."
Higgins took the first seven frames against Joe Perry but insisted the match was a lot closer than the 9-3 final score suggested.
"It could easily have been 4-4 after the first session, because Joe missed three or four good chances," he said.
"I managed to get in and clear up and that's what won me the match basically - a few clearances under pressure."
Perry produced a break of 128 in the 10th frame to offer some resistance but Higgins closed things out with a break of 106 to claim victory.