The shell-shocked Jillaroos were in unfamiliar territory after their seven-year winning streak against New Zealand was ended with a 12-6 loss in their Pacific Championships rugby league clash in Melbourne.
Only three players in the Australian side -- skipper Ali Brigginshaw, prop Kezie Apps, and lock Simaima Taufa -- had ever tasted defeat with the side unbeaten in their last 14 matches dating back to 2016, when they last fell to the Kiwis.
Rookie Ferns winger Leianne Tufuga scored her first international try with seven minutes left on the AAMI Park clock on Saturday night to break a 6-6 deadlock and secure the victory.
"We haven't lost a game for seven years so it's a long time," said Australia coach Brad Donald.
"Most of those players in that change room don't know what a loss feels like in this jersey.
"So that'll make us bigger and stronger in the years to come."
With no women's final or a third Test between the teams and with a win apiece, the sides also finished level on points differential after Australia won their first clash in Townsville 16-10.
It looked like New Zealand could be scrambling for a match-winner after their first-half tryscorer, Mele Hufanga, was forced off late in the match for a HIA.
Tufuga's try was set up by Apii Nicholls, with the Ferns' superstar fullback firing a long ball out for her winger, who still had work to do to plant the ball across the line.
Uncharacteristically poor in attack, only completing at 53 percent for the match, Australia couldn't find a late try to level.
Donald said the team had a focus on improving their defence after their first clash with NZ, but it came at a cost.
"We were better defensively -- our tackle efficiency in the first half was 97 per cent but we only completed four out of 14 sets so we we played like strangers with the ball but showed up for each other defensively," he said.
"Hats off to the Ferns as they just kept showing up and kept denying us at the last minute."
The home side took an early lead through their own winger Jaime Chapman, who charged over in the ninth minute with the Kiwi defence caught short.
Dally M Medallist Tamika Upton looked to have scored Australia's second try before the bunker ruled the fullback had lost the ball.
In the last minute of first half Tiana Davison stripped the ball from Brigginshaw early in the tackle count.
The Kiwis then opted to run the ball on the last tackle and Brisbane centre Hufanga, who has represented Tonga in rugby union, was unstoppable close to the line for a 6-6 half-time score.
Nicholls was also denied a try in the second half due to obstruction but the fullback still had a hand in their match-winning effort, orchestrating the try for Wests Tigers winger Tufuga in the 62nd minute.
The Jillaroos also finished with three players -- Jess Sergis, Kezie Apps and Olivia Kernick -- on report.