Barry Hawkins suffered an early exit from the Northern Ireland Open when losing 4-3 to rookie to Chen Zifan in Belfast.
Breaks of 99, 92 and 80 had put Hawkins on the verge of victory at 3-2 but Zifan fought back to pinch the sixth frame before holding his nerve to win a scrappy decider.
Mark Allen was also dumped out, losing 4-1 to Niu Zhuang.
Allen was not at his best but looked set to get out of jail when 3-1 down, forcing two snookers to breathe new life into the game.
However, it was Niu who got the better of a safety battle as a double on the blue effectively sealed a surprise win.
Perhaps the biggest surprise was to come in the evening, though, as Rory McLeod beat John Higgins for the first time in his career.
From 2-1 down, McLeod won three frames in a row to advance as Higgins' woes continue.
Stephen Maguire was another big-name casualty in the first round as Micheal Holt got the better of their scrappy encounter to win 4-2 while Anthony MaGill was whitewashed 4-0 by Alexander Ursenbacher.
Kyren Wilson has been busy of late and saw his hectic schedule catch up with him when he lost 4-3 to Lee Walker while Stuart Bingham was a long way below his best when crashing out 4-2 to Peter Lines.
There were no such alarms for reigning champion Mark Williams as breaks of 91, 69 and 91 were good enough to see him ease past Alfie Burden 4-2.
Don't let @markwil147 fool you...
— World Snooker (@WorldSnooker) November 12, 2018
The game is not as easy as the World Champ often makes it look! #NIOpen @Eurosport_UK pic.twitter.com/FyJQaKuLDS
Elsewhere, Sam Craigie rattled off breaks of 115, 78 and 71 in his 4-0 defeat of Adam Duffy while Micheal White beat Mark Joyce by the same scoreline.
