The two finalists had conceded just two tries each going into the final, but that didn’t stop them from going all-out in attack in their bid for glory.
Kelly Brazier stretched over the line to give the Black Ferns an early lead, but Australia hit straight back through Maddison Levi.
Caslick’s quick hands then sent Levi over the try line for a second time, but New Zealand fought back through Stacey Fluhler as the Aussie 7s went in at the break with a slender two-point lead.
A yellow card for Niall Williams early in the second half gave Australia a chance, and they took full advantage as the RWC Sevens 2022 top try scorer Faith Nathan scored her ninth try of the weekend before Levi powered down the wing to complete her hat-trick.
That quick-fire double gave the Aussies a commanding 14-point advantage with three minutes to go, but the Black Ferns would not give up without a fight and narrowed the gap thanks to a super break and finish from Shiray Kaka.
Australia’s performance was plagued by a high penalty count against them, giving New Zealand repeated chances to attack for a game-levelling score, which they eventually found in the final play when Alena Saili crossed.
Tenika Willison needed to nail the conversion to take the game to extra-time but steered it wide, sparking euphoric scenes from the gold-shirted players.