Dechawat Poomjaeng produced a stunning first-round upset at the China Open with a 5-4 win over world number three Neil Robertson.
Australian star Robertson has won snooker's Triple Crown - the World and UK Championship and the Masters - and also took this title in 2013 and was runner-up last year.
But despite leading 3-1 at the interval, with breaks of 56 and 63 in frame four, he was pegged back by Poomjaeng.
The popular and eccentric Thai player made breaks of 40 and 30 in the first frame back, levelled the match in a scrappy sixth frame and led for the first time after a 74 in the next.
Robertson responded with a 74 of his own and led with a 44 in the decider, but Poomjaeng responded with 48 and won the frame and match on the final black.
Home favourite and reigning champion Ding Junhui had no such trouble in Beijing, beating Scotland's Marcus Campbell 5-1.
Ding took the first frame after forcing Campbell into a dangerous pot attempt and finally got across the line in a messy second frame to lead 2-0 - despite an unlucky foul on the black extending the frame.
The third followed as a 66, Ding's highest break of the match, brought him back from 47-0 down but Campbell finally got on the board in the frame before the interval.
The Scot, sporting a Union Jack bow-tie, was doing enough to prevent Ding reaching his fluent best but breaks of 41 in frame five and 58 and 50 in the next clinched victory.
Ali Carter was beaten 5-4 by Norway's Kurt Maflin despite making three breaks over 60.
Carter led three times and was within a frame of victory at 4-2, but the key moment came when he made 66 in frame seven but Maflin came back to win it and went on to take the match.
Alan McManus was also beaten from 4-2 up by youngster Jack Lisowski.
Some typical strangling safety play got the Scot, known as "Angles", off to a good start and breaks of 54 and 80 took him to the verge of victory.
But Lisowski levelled with runs of 78 and 56 and then won the deciding frame as well.
Barry Hawkins made breaks of 80, 81, 76, 47 and 124 in an emphatic 5-2 victory over Gerard Greene.
There were also straightforward wins for Stephen Maguire, Ricky Walden and Ryan Day, while Dominic Dale, Peter Ebdon, Mark Davis, Mike Dunn and Gary Wilson also progressed.
Zhao Xintong, Zhuo Yuelong, Peter Lines and Robin Hull came through the wild-card round to reach the main draw