Teenager Luke Littler suffered a surprise defeat in the European Championship first round, losing 6-4 to Andrew Gilding in Dortmund.
Gilding showed a clinical edge and raced into a 3-0 lead against his English compatriot, the run including a 12-darter in the second leg but was pegged back as Littler responded with three straight legs of his own.
Gilding then regained momentum with an 11-darter and, despite Littler then levelling once more, saw out the next two legs to win and set up a meeting with home favourite Ricardo Pietreczko in the second round on Saturday.
In contrast to Littler, world champion Luke Humphries cruised through with a comfortable 6-2 win over Nathan Aspinall.
Humphries threw seven 180s and finished with a 46% checkout rate in a dominant display.
He will now face Welshman Jonny Clayton, who beat Chris Dobey 6-4 to advance.
However, Scottish defending champion Peter Wright will be absent from the latter stages, he finished with a disappointing average of below 75 as his bid to win a third European Championship title ended with a 6-0 loss to Jermaine Wattimena.
Dutchman Wattimena will face England's James Wade in the next stage.
Danny Noppert 6-2 Joe Cullen
Chris Dobey 4-6 Jonny Clayton
Rob Cross 3-6 James Wade
Ricardo Pietreczko 6-5 Damon Heta
Peter Wright 0-6 Jermaine Wattimena
Luke Littler 4-6 Andrew Gilding
Luke Humphries 6-2 Nathan Aspinall
Josh Rock 1-6 Mike de Decker