Price, the 2022 winner, launched his bid for a second title with a 103.6 average and seven 180s in a 6-4 victory over the DPNZ number one at the Spark Arena.
He came within a whisker of perfection in the fifth leg, missing double 12 for a nine-darter, before holding off a spirited rally from the home favourite.
“The atmosphere was buzzing tonight,” reflected Price, who will take on Northern Ireland’s World Cup champion Josh Rock in the last eight.
“I felt like I was playing really well, but Jonny hit some timely finishes and kept himself in the game.
“I’m here to win, I’m here to give it my all, and hopefully I’ll lift that trophy tomorrow.”
Rock impressed on his Auckland debut, averaging just shy of a ton to beat qualifier John Hurring 6-2, sealing a second successive World Series quarter-final.
It was a clean sweep for the eight PDC representatives against their Oceanic opponents, though Humphries laboured in a 6-3 win over New Zealand’s number one Haupai Puha.
The world number one rattled off four legs on the spin to take control and survived an 11-darter from Puha before closing out the match.
“Hopefully tomorrow I can be the Luke Humphries that everybody knows,” declared the reigning champion.
“It’s no secret that I’m going through a difficult patch at the moment.
“It’s hard work because I’m struggling through it, and maybe I’m trying too hard, but one good day tomorrow and everything can change.”
Luke Littler kept his hopes of consecutive titles alive with a 6-4 win over Mark Cleaver, producing back-to-back 13-darters to fend off the veteran.
Stephen Bunting moved closer to topping the World Series rankings, grinding out a 6-3 win against Ben Robb to set up a meeting with Chris Dobey, who overturned a deficit to beat Australian stalwart Simon Whitlock 6-4.
Mike De Decker, runner-up at last week’s Australian Masters, thrashed Gordon Mathers 6-1, while Damon Heta matched the scoreline against debutant Dean Reyland.
Saturday’s finale will cram in the quarter-finals, semis and final, with Humphries meeting Heta in a repeat of last year’s showpiece.
Littler faces De Decker again after their Sydney showdown, while Price’s clash with Rock and Bunting’s tie with Dobey round out the last eight.