Adrian Lewis moved into the last 16 of the PDC Darts World Championship with a 4-1 win over Denis Ovens.
The defending champion is looking for a third successive world title and will face Kevin Painter in the next round.
"I found it a real struggle out there, but I got the job done," Lewis said.
2004 finalist Painter beat Ronnie Baxter, Simon Whitlock progressed against Colin Osborne and Dutchman Raymond van Barneveld got past Brendan Dolan.
Despite progressing to the third round at Alexandra Palace, 27-year-old Lewis, from Stoke, was unhappy with his performance.
He said: "I know that I have to improve and I will get back on the practice board over Christmas, ahead of my game against Kevin.
"I know that if I play like I did tonight then I will be out."
Australian Whitlock progressed to the last 16 with a straight-sets victory over Osborne.
The 37-year-old Englishman managed just four legs in the contest as Whitlock put in a strong performance, including a 164 checkout.
Whitlock said: "I've put in a great deal of practice in preparation for this tournament and I'm very happy with the way things have been going at the moment."
Elsewhere, Wes Newton sealed a one-sided 4-0 win over Scott Rand and Colin Lloyd defeated Mark Webster 4-2 to seal his place in the last 16.