The Australians won the third quarter, 15-9, which effectively decided the final.
New Zealand put goal shoot Cathrine Latu on for the fourth quarter in a last-gasp bid.
Latu has been out with a calf injury since the third group game and briefly showed what the Silver Ferns had been missing.
But it was too late to do much about the outcome by then, as Australia, 11 up at the start of the last quarter pressed on relentlessly to end ambitions of a Silver Ferns hat trick.
At quarter time it was 14-14 and as tight as that suggests.
Australia had the beanpole shooter Caitlin Bassett as an obvious target and attacking hustlers in Natalie Medhurst, Madi Robinson and Kim Ravaillon as support acts.
New Zealand opted for Maria Tutaia at goal shoot and Jodi Brown at goal attack. It was a bold call, considering the last time Tutaia started an international at goal shoot was in 2008. Space was at a premium.
Goal keep Leana de Bruin had her hands full with Bassett while captain Casey Kopua was working overtime to break down the service into the key shooter.
Just as the semifinal win over England was desperately tight, so too was the final, at least till halftime to absolutely no surprise.
Late in the second quarter, Australia got a small run and by halftime were 28-24 ahead before the key third quarter decided it.
New Zealand's attackers were pressured into errors by the rugged defence of Laura Geitz and Julie Corletto. Three successive shots were missed and that was the opening Australia needed as they bolted to a 10-goal advantage, which they extended in the final period.
Earlier, England's miserable Games campaign ended in disappointment. Having lost to Australia and New Zealand by a solitary goal, they were beaten in the bronze medal match by Jamaica, 52-48.