Richard Veenstra enjoyed a memorable debut at the Lakeside when he dumped third seed Jeffrey de Graaf out of the BDO World Professional Darts Championships.
Dutchman Veenstra got the better of his compatriot, who produced a 10-dart finish early in the third set, in a 3-2 thriller to book a last 16 clash with England's Martin Atkins, who enjoyed a straight sets victory over 14th seed Pip Blackwell.
For De Graaf it was a fourth successive first-round defeat and he is yet to win a match at Lakeside.
There was little difficulty for fourth seed Jamie Hughes as another Englishman progressed without dropping a set, in his case at the expense of Scotland's Ross Montgomery, while Welsh 10th seed Martin Phillips also won 3-0 against veteran Ted Hankey.
However, American Larry Butler was taken all the way before eventually seeing off Holland's Ryan de Vreede 3-2 to book a showdown with top seed Glen Durrant.
Earlier, former World champion John Walton had eased his way through the preliminary round with a 3-0 whitewash of Australian No.1 Rob Modra, and the 54-year-old Englishman, who dropped just three legs, will face compatriot Brian Dawson in the last 32.
Sheffield-based Walton, 54, last appeared at the Lakeside in 2013 and had not won a World Championship match for five years before defeating Modra.
In the women's draw, fourth seed Aileen de Graaf saw off the challenge of England's Casey Gallagher with a 2-0 win to secure an all-Dutch quarter-final clash with Anca Zijlstra.