Defending PDC World Championship winner Gary Anderson came through a high-quality encounter against Daryl Gurney 4-1 to book his spot in round three.
Scot Anderson was made to work for his victory in front of a boisterous Alexandra Palace crowd, but he showed his quality with checkouts of 170, 155 and 100 during the match.
Gurney averaged over 100 en route to taking the first set 3-2, but the world number two levelled the match by winning the second by the same scoreline - including his excellent 170 finish in the second leg.
Northern Irishman Gurney missed darts to clinch the deciding leg of the third set and that proved crucial as Anderson started to pull clear, missing treble 19 when on a nine-dart finish.
A 155 finish handed Anderson the break at the start of the fourth set, but Gurney fought back to set up a deciding leg.
But, when Gurney failed to take out 136, Anderson swept up double 12 to seal the win.
Dave Chisnall was in excellent form in his 4-1 beating of Christian Kist.
The Englishman averaged just shy of 103 and hit 12 maximums, while finishing the match with a 97 checkout.
Jamie Caven whitewashed Ricky Evans 4-0 in a fine display and will play either James Wade or Wes Newton in the last 16.