World champion Mark Williams suffered a first-round defeat against world number 65 Sunny Akani at the International Championship in Daqing, China.
Williams said Akani, 23, "pots everything" after the Thai made two centuries in the last three frames to seal a 6-3 victory.
World number one Mark Selby thrashed Ken Doherty 6-0, recording three centuries and two fifties.
There was also a 6-0 win for Judd Trump against Scotland's Alan McManus.
Selby will play fellow Englishman Robert Milkins in the round of 32, while Akani faces a match against China's world number 32 Zhou Yuelong and Trump takes on Michael Holt.
Stuart Bingham, who won the English Open earlier this month, was beaten 6-3 in the opening round by Israel-born Scot Eden Sharav, the world number 79.
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