Fifth seed Clayton, who qualifies for the last-16 of the championships for a fifth successive year, had to be somewhere near his best to beat the Dutchman in a nip-and-tuck third round affair.
Clayton was back in action after a 12-day break, having received a bye through to round three because his second-round opponent, Dom Taylor, was suspended for failing a drug test.
The Welshman had looked to gain the advantage by moving a set up three times, only for Zonneveld to level on each occasion.
But the 51-year-old held his nerve to clean sweep the deciding set and claim a 4-3 triumph, where he finished with match stats of 11 180s, averaging 98.44.
Clayton might be a regular in the fourth round, but he has never progressed beyond the quarter-finals at Alexandra Palace, and the four-time major winner knows he must improve to break his duck.
“I’m going to prove myself, I’ve had a few down years,” said Clayton after the contest.
“Hopefully, I’m going the right way. I’m looking forward to every time I walk on this stage, and I feel good.
“There’s a lot of loose darts, low scores. I need to get rid of them. You need those two treble visits and the more I get used to that and keep doing that then it gives me a little bit more of a chance.”
Zonneveld had knocked out former world champion Michael Smith to reach this stage, and Clayton said afterwards, “I was thinking ‘Niels, please let me win this, please!’”
Clayton will next face Swedish debutant Andreas Harrysson, who defeated Germany’s Ricardo Pietreczko 4-2.
[Lead image: PDC]
