The new-look Silvers Ferns defied pre-tournament sceptics as they claimed their first win over the hotly-favoured Cup hosts in their last 10 meetings.
If the Diamonds had been under any impression that winning a third consecutive world title at home would be straightforward, they received a cold reality check in front of a world-record crowd of 16,233 at Allphones Arena.
Australia had been unsure of what to expect from the Silver Ferns' revamped line-up, which had not been put under pressure until Sunday.
What they got was a clinical and unforgiving display from an outfit that, while making some errors, left Australia chasing throughout the entire nail-biting contest.
The loss is the Diamonds' first to the world No 2 Silver Ferns in nearly two years, with the last coming in September 2013.
It also means their trans-Tasman rivals finished at the top of Pool A and take a psychological edge as they head into the qualification rounds starting Tuesday.
Despite Erin Bell's impressive claim to the starting goal attack bib in Australia's opening two fixtures, coach Lisa Alexander reverted to regular campaigner Natalie Medhurst in combination with her West Coast Fever teammate Caitlin Bassett at shooter.
The decision paid off, with the pair feeding each other seamlessly in the circle and Bassett slotting 38 goals.
But New Zealand brought the defensive pressure further down the court, and formidable Kiwi centre Laura Langman combined with wing defence Kayla Cullen to crucially stop feeding engines Kim Ravaillion and Kim Green from doing their jobs.
The Silver Ferns pounced on Australia's unsteady start, building momentum throughout the second quarter as the Diamonds struggled to get the ball into their attacking third.
An initially nervous-looking Silver Ferns goal attack Maria Tutaia found her eye, sinking some sublime long-range goals.
Australia's high penalty count also cost them dearly, racking up 17 contacts to their opponents' five in the first quarter alone, with captain Laura Geitz the main offender.
The Australians rallied late with the help of stints from the feisty Sharni Layton and Paige Hadley, but couldn't peg back the Kiwis.
