Matthew Stevens fought back from four frames down to claim his place in the quarter-finals of the Shanghai Masters.
Matthew Stevens faces Ryan Day in the quarter-final
The Welshman was trailing 4-0 to Scotland's Stephen Maguire but staged an incredible fightback to win 5-4.
Stevens will now play compatriot Ryan Day in the last eight. Day beat Ian McCulloch of England 5-3 to go through.
And Dominic Dale made it a hat-trick of Welsh victories, cruising past England's Adrian Gunnell 5-1 to set up a quarter-final clash with Dave Harold.
I can't believe what happened...I was out of the match
It's the first time in Stevens' 13-year career that he has come from 4-0 down to win a ranking event match 5-4.
"I can't believe what happened," he said. "At the interval I was out of the match. At the Crucible I lost 13-12 to Shaun Murphy from 12-7 up so that shows what a crazy game this is."
Elsewhere Stephen Lee will face Graeme Dott with Mark Selby playing Stuart Bingham in the other quarter-final.