Lee Walker deservedly beat Mark Selby as the last 64 of the World Open reached its conclusion on Tuesday in China.
The Welshman took full advantage of the out-of-sorts world champion to seal a 5-2 victory and move into the second round in Yushan.
Selby, who has struggled so far this season having failed to reach beyond the last 16 of a ranking event so far, was a shadow of the self that dominated the circuit last term in the process of winning a third Crucible crown.
The 34 year-old’s safety, in particular, was nowhere near his best and Walker duly capitalised despite being unable to conjure up any meaningful breaks of his own.
The 41 year-old, quarter-finalist at the World Championship 20 years ago, held his nerve well with some astute potting and careful tactical play to set up a last 32 tie against Robert Milkins.
Home favourite Ding Junhui briefly looked to be in trouble as well before coming through against Zhang Anda 5-3.
Ding raced into a 4-0 lead at the mid-session interval, helped by a superb 128 in the opening frame, but allowed his challenger back into the contest through a series of scrappy exchanges.
It looked like his younger countryman was going to force a decider, only for a neat 55 clearance in the last saw Ding fall over the winning line.
There was another major shock on day two, though, with Shaun Murphy bowing out to Daniel Wells, also by a 5-3 scoreline.
Murphy had been one of the in-form players of the campaign with two ranking event final appearances to his credit, but didn’t have his scoring boots on as the Welshman bagged one of the best victories of his career.
China’s number two Liang Wenbo disappointed as well, with China Championship semi-finalist Li Hang compiling runs of 58 and a superb 102 in the last to beat his compatriot in a decider.
Northern Ireland Open champion Mark King was also sent crashing, squandering a 3-1 mid-session cushion to lose 5-3 to Chen Zhe.
Most of the other results on a busy day of action went according to plan.
John Higgins continued his fine run of form of late with a 5-0 destruction of Alexander Ursenbacher while Mark Allen was equally ruthless against Oliver Lines, losing just the solitary frame in a 5-1 triumph.
Stuart Bingham and Anthony McGill, meanwhile, earned respective 5-2 victories over Alfie Burden and Duane Jones, with five-time ranking event winner Stephen Maguire repeating the trick against Ken Doherty.
Martin Gould hammered Jack Lisowski 5-1 while there were closer passages through to the next stage for Marco Fu and Joe Perry.
Fu managed a 5-3 defeat of Ian Burns and Perry was taken the distance by Yu Delu, holding off a spirited fightback by the Chinese player with an 84 break in the final frame shoot-out.
Elsewhere, Thepchaiay Un-Nooh, Jimmy Robertson, and Cao Yupeng were all victorious and advanced into the last 32.
Live coverage continues on Eurosport.