Down 2-0 in the series, the clash was a dead rubber, but will give the New Zealand side confidence going into the three-match ODI Rose Bowl series as they claimed their first victory over Australia in any format since February 2017.
Kerr was the hero. After being put on strike needing seven to win from five balls, she smacked Megan Schutt over mid-off for four, before slapping her through the leg side for another boundary to seal a five-wicket win with three balls to spare.
It was arguably closer than it should have been after the Kiwi bowlers did well to restrict Australia to 123-7, with Kerr (2-18 from four) a standout and supported by sister Jess (0-15 from three) and Lea Tahuhu (2-29 from four).
Sophie Devine and Maddy Green picked up a wicket apiece as well, but couldn't get the White Ferns off to a fast start when opening with the bat, with Devine making 25 from 22 balls before being stumped from some canny bowling from Georgia Wareham, while Green mustered just 10 from 17.
Suzie Bates' struggles continued with just three from eight balls, but Amy Satterthwaite (30 from 25) and Katey Martin (23 from 24) brought the hosts back to needing 30 runs from 30 balls.
However, they fell in quick succession, with Wareham, surprisingly only used for three overs, bowling Martin, and Satterthwaite dragging on to the similarly impressive Jess Jonassen (1-15 from four).
That left Kerr and Hayley Jensen needing 26 from 22 balls. The pair had been in this situation before, nearly seeing the White Ferns home from an improbable position against India at the Twenty20 World Cup earlier this year, and this time they went one better as Kerr broke the Ferns' drought.
The two teams resume their rivalry in the Rose Bowl – which New Zealand hasn't won since 1999 – on Saturday.
