World number 51 Xiao Guodong defied a broken hand to dump Judd Trump out in the second round of the PTC Grand Finals in Galway and reach the first quarter-final of his career.
But there was disappointment for Galway snooker fans as Ronnie O'Sullivan withdrew from his scheduled second-round match against Ricky Walden after contracting glandular fever.
Chinese player Xiao stormed to a 4-2 win despite ignoring doctors' advice not to play snooker after breaking a bone in his hand whilst sleeping awkwardly three weeks ago.
Xiao hit an early century break to put the pressure on Trump as he eased into a 3-1 lead.
World number three Trump came back to 3-2, but Xiao held his nerve in the next after a safety exchange.
Xiao told worldsnooker.com: "I've been playing for five years and this will be my first quarter-final. I'm surprised because it has happened now when I am playing with a broken hand.
"Judd didn't play as well as he can today but he is a very good player so it was still hard to win. I tried not to think about the match or ranking points, I just wanted to win the match."
O'Sullivan's withdrawal was accepted by tournament officials and automatically sends Walden through to the quarter-finals where he will play Stephen Maguire, who beat Mark Davis 4-2.
Earlier, Mark Selby moved into the last eight with a 4-1 win over Ding Junhui.
Ding took the first frame with a break of 75 but Selby won four in a row to earn a tie against Stephen Lee.