Once again proving too strong and too classy, the Black Ferns preserved their proud 32-year undefeated record against the Wallaroos with a never-in-doubt 40-5 win in Queensland on Saturday night.
Flanker Siokapesi Palu scored Australia's lone try in a typically inspirational captain's display.
New Zealand's six-tries-to-one drubbing followed up the Wallaroos' 24-0 loss to Canada and 33-12 defeat to the USA in the cut-throat round-robin tournament featuring four of women's rugby's top eight nations.
The Wallaroos had been hopeful of celebrating lock Michaela Leonard's milestone 46th Test with a watershed win over the all-conquering Kiwis.
Instead, Leonard eclipsed prop Ashley Masters to become the most-capped Wallaroos player in history in an all-too-familiar loss to the Black Ferns, this time at Sunshine Coast Stadium.
In interim coach Sam Needs' final Test in charge before Rugby Australia names a permanent replacement after the series, the Wallaroos trailed 29-5 at the break.
First-half tries to centre Amy du Plessis and flanker Liana Mahutariki-Fakalelu, either side of a double to winger Ayesha Leti-I'iga, did the damage for New Zealand.
Lock Laura Bayfield and winger Justine McGregor completed the 45-point demolition job in the more competitive second half from the Wallaroos.
"Look, despite the score, despite the 30 wins in a row, that was actually a really hard game out there," said gracious NZ captain Kennedy Tukuafu.
"We know that Australia have nothing to lose coming into this game. It's their first game at home for the season and we knew that they were going to come out exactly like that with nothing to lose."
Preferring only to look ahead, Leonard was philosophical in defeat.
"We came with a plan and we did that," Leonard said.
"We've got to give credit to New Zealand. They're a world-class team for a reason, and they definitely outperformed us.
"But there's glimpses of positives. We've done really well to put together a performance with the little time that we've had.
"It's just up to us to go into our Super season, play well, and then look forward to the World Series."