Michael Holt stunned Ronnie O’Sullivan in a first round decider of the World Grand Prix on Tuesday.
The Englishman raced into a 3-0 lead with breaks of 88 and 119 but watched as his opponent rallied to force a final frame.
There, one would have backed O’Sullivan to continue his dominance of 2016 so far but the 40 year-old missed to the middle pocket, allowing Holt in for a 76 to clinch a memorable win.
It marked only the second time that Holt has beaten the Masters and Welsh Open champion throughout his career, and the 37 year-old will play either Liang Wenbo or Graeme Dott for a quarter-final berth in Llandudno.
Meanwhile, Australian Neil Robertson also suffered an early exit as the UK champion fell 4-3 to Peter Ebdon.
The encounter was a drab, scrappy affair for the most part with Ebdon taking advantage of his chance in the last frame to seal his progress.
The former world champion will play Ding Junhui in the last 16 after the Chinese continued his mini return to form with another 4-3 success, this time over Ben Woollaston.
Ding needs good performances in each of the last three ranking events before the World Championship if he is to secure automatic qualification for the Crucible.
One player who looks in increasing danger of missing out and being forced to contend the dreaded qualifiers at Ponds Forge is Scotland’s Stephen Maguire, who was thrashed 4-0 by countryman John Higgins.
Maguire hasn’t qualified for the Players Championship so will be relying on a deep run in the China Open to maintain his place among the world’s top 16.
Elsewhere, there were other whitewash victories for Martin Gould and Joe Perry while home hope Ryan Day enjoyed a 4-1 triumph over Matthew Selt.
Northern Ireland’s Mark Allen won the last three frames as he came from behind to beat David Grace 4-2.
Wednesday will see the remaining first round clashes completed with the likes of defending champion Judd Trump, Mark Selby and Shaun Murphy entering the fold.