Mark Allen was stunned by Dominic Dale as he crashed out of the ManBetX Welsh Open in the third round.
The Antrim potter was unable to follow up his first and second round wins over Andrew Higginson and James Wattana at Cardiff's Motorpoint Arena, succumbing to a 4-2 defeat in the last 64 against a player ranked 84 places below him.
Home favourite Dale had raced into a 1-0 lead after a steady break of 56, before the world No.7 found his usual cueing fluency to restore parity with a fine 101.
And a third-frame 92 then saw the five-time ranking event winner seize the advantage, before a further break of 62 in the fourth opened up daylight between the pairing. But Dale replied with a fourth-frame 70 of his own to make it two frames apiece, before limiting Allen to a total of just 52 points across the final two frames to march to a surprise victory.
The result continued Allen's stop-start season at the table, reaching the semi-finals at the Betway UK Championship and 19.com Scottish Open but suffering premature exits at the Dafabet Masters and failing to qualify for events in Germany and Austria.
The former world No.5 will head to the Snooker Shoot-out in Watford next week, as the countdown intensifies to the Betfred World Championship at the Crucible in April.
Fellow Northern Irishman Gerard Greene was also knocked but opponent Neil Robertson believes there was nothing more he could have done.
Greene was on the receiving end of a searing performance by the world No.2, who crafted majestic breaks of 121, 116 and 85 to triumph 4-0 and move into the last eight.
The world No.108 had enjoyed a promising run to the fourth round, beating Liang Wenbo, Daniel Wells and world No.16 Ali Carter to confirm his best ranking event performance since 2018.
And despite going down to a heavy loss against the in-form 2010 world champion, Robertson says there was no way Greene could have prevented the defeat.
“It was perfect snooker from me, really - I’m very happy with that but I didn’t really expect it,” he said.
Watch the Welsh Open live on Eurosport and Eurosport Player with analysis from Jimmy White and Neal Foulds