Gary Anderson's defence of the World Darts Championship came under a stern examination in a thrilling contest that saw the Scotsman prevail 5-3 against Dave Chisnall to reach the semi-final.
Anderson is chasing a third successive crown at the Alexandra Palace but was tested in a win which sent him through to the last four..
It was a 180-fest as the pair threw 33 maximums between them, one short of the record in the history of televised games.
Things looked good for Anderson when he checked out on 104 to claim the first set against the throw before holding to take a 2-0 lead.
Chisnall fought back to 2-2 before another sizeable finish - a 124 checkout on the bull - from Anderson restored his lead only for his opponent to respond again.
A NEW RECORD! Gary Anderson is now unbeaten on the Alexandra Palace stage for 16 games. pic.twitter.com/7huTMC2Rxf
— PDC Darts (@OfficialPDC) December 30, 2016
With both players averaging well over 100, Chisnall was on a roll and found himself in a great position to go 4-3 up but he crucially missed four doubles and Anderson stole the set.
He then ran away with the final set to tee up a last-four date with Peter Wright.
Wright edged out James Wade 5-3 in the afternoon's other quarter-final.
It was another keenly-contested game as Wright was one arrow away from landing the first nine-darter of the tournament while Wade won one set with checkouts of 144 and 155.
Wright assumed control with back-to-back sets and he saw it out.
In the evening session, Michael van Gerwen eased into the semis with a convincing 5-1 win over Daryl Gurney – the last man to beat him in any competition.
Van Gerwen looked in the mood for a short night's work from the first set, checking out in 101, 92 and 170 to take it 3-0 in just 4min 5sec and a total of 36 darts.
