World number one Luke Humphries suffered a shock defeat to Gabriel Clemens at the Hungarian Darts Trophy, where Michael van Gerwen later landed a nine-dart finish as he coasted into the last 16.
Humphries just missed out on the PDC European Tour event title last year when beaten 8-7 in the final by Dave Chisnall, and was soon up against it when Clemens broke throw in the opening game.
Although world champion Humphries fought back to level and then lead 4-3, German Clemens broke again to edge 5-4 in front before taking victory against the darts in the deciding leg.
Clemens will face Van Gerwen in the last 16 after the Dutchman demolished Martin Lukeman 6-2 – having landed a perfect nine darts in the opening leg and averaging 104.
Peter Wright continued his fine recent form on the back of his German Darts Championship victory with a 6-0 whitewash of Australia's Damon Heta to coast into the last 16.
Gerwyn Price, another former world champion, crashed out after Dutchman Wessel Nijman came from 5-2 down to take a last-leg decider.
Top seed Chisnall ended the hopes of Jonny Clayton – who had beaten world number two Michael Smith in his opening match – with an impressive 6-1 win, hitting an average of just over 100.
In the opening match of the evening session at the MVM Dome, Danny Noppert held off a fightback from Nathan Aspinall to win 6-4.
Ross Smith beat Raymond van Barneveld before Rob Cross celebrated his 34th birthday with a 6-1 victory over Andrew Gilding to finish off the evening action.
Earlier on Saturday, Josh Rock came from 5-2 down to beat James Wade in a final leg after 'The Machine' had missed eight match darts and Dutch-born Norwegian Cor Dekker hit a nine-dart finish in his 6-2 defeat by Stephen Bunting.
The last-16 games will take place on Sunday afternoon before the tournament concludes with the quarter-finals onwards into the evening session.