Three-time world champion Mark Williams saw the defence of his Cazoo British Open title end at the second round stage as he was beaten by Ben Woollaston on Tuesday.
The Welshman went down 4-1 in a disjointed performance at the Marshall Arena in Milton Keynes.
Williams did take the opening frame after a break of 78 but he was unable to maintain any consistency as world number 44 Woollaston claimed four in succession.
John Higgins, the four-time world champion, joined him in exiting prematurely as he was beaten 4-3 on the final black by Yuan Sijun.
The Scot, who clocked up his 900th career century as he fought back from 2-0 down, led 64-8 in the decider but then missed a red that would have left Yuan needing snookers. The Chinese player took advantage to snatch victory 66-64.
Another former world champion, Stuart Bingham, also tumbled out as he was beaten 4-1 by Zhao Xintong, who compiled three centuries in a convincing win.
Mark Selby had no such problems as he saw off Mark Joyce 4-1 with breaks of 110, 74, 55 and 54. Barry Hawkins also scored heavily as he beat Kyren Wilson by the same scoreline, knocking in runs of 72, 120, 78 and 134.
