Michael van Gerwen and Michael Smith progressed into the last 16 of the European Championship but Gerwyn Price crashed out in the opening round.
Van Gerwen is chasing a first televised major of the year and opened with a classy 6-1 victory over Gabriel Clemens in Dortmund.
The Dutchman, who has won this tournament four times, averaged 100.10 in his routine win which saw him set up a second-round meeting with Gary Anderson.
“You always need to be sharp in this short format,” said Van Gerwen, one of five former champions in the 32-player field.
“I am enjoying my darts again and I think you need to have that if you want to perform well.
“You want to keep performing well, because there’s still a lot to fight for, and I think this is a really important tournament for me.”
Anderson, a two-time world champion, also averaged over 100 in his 6-3 success against Stephen Bunting.
The Scot said: “Me and Michael have had some belters; apart from winning the World Championship, the best game I ever played in was when I beat Michael in Dubai.
“It would be fantastic to get my hands on this title, but there’s no pressure and no expectation on me.”
Smith barely had to break sweat as he demolished Dave Chisnall 6-0.
Smith had one of the toughest opening-round draws but made light work of it, with three ton-plus checkouts, including a 161 to dispose of Chisnall.
Price was an early casualty, though, losing 6-3 to Daryl Gurney while Martin Schindler, the top seed in this tournament based on his performances on the European Tour, was ousted by Dirk van Duijvenbode.
There were also wins for Ritchie Edhouse, Luke Woodhouse and Ryan Searle.
World champion Luke Humphries begins his campaign on Friday in an exciting first-round clash with Nathan Aspinall. Luke Littler will also be in action as he takes on Andrew Gilding.
When is darts next live on Sky Sports?
Live darts returns to Sky Sports with the Grand Slam of Darts in Wolverhampton from November 9-17 as Luke Humphries looks to defend his title. Stream Sky Sports live with no contract on a Month or Day membership on NOW.