Two tries in the opening five minutes did the damage, and there were four more before half-time to send the Jillaroos to the break with a commanding 34-6 advantage.
Despite applying pressure, they were unable to add to their score as the humid conditions in Brisbane took their toll and errors crept in.
But Australia had done enough to ensure a fourth straight title, beating the Kiwi Ferns in the final each time, to reinforce their status as the sport's powerhouse nation.
"I want to thank the Kiwi Ferns. It's been such a great rivalry for so many years now, with so much respect between the two of our teams," said Australia captain Isabelle Kelly, now a three-time World Cup champion.
"To my team ... I'm just so humbled and honoured to be able to lead you guys. This has definitely been a dream come true, and I knew that we could get the job done."
Before Australia's global rise, New Zealand won the World Cup in 2000, 2003 and 2008.
"We didn't quite get the job done today, but we are going to assert dominance back into this jersey," said New Zealand skipper Raecene McGregor.
"The best of the Kiwi Ferns is yet to be shown, so stay with us."
New Zealand had won only one of their previous 12 Tests against the Jillaroos dating back to 2017, and they were under the pump immediately.
A knock-on near the New Zealand try line just two minutes in allowed Australia to spread the ball wide, and Chapman dived over in the corner for her 11th try of the tournament.
With all the momentum, Australia pressured another mistake from New Zealand and capitalised with Shaylee Bent crashing over for their second converted try.
Midway through the first half, they were 18-0 ahead, with another Chapman special on the back of a lightning break.
A sensational solo effort from Jessica Sergis stretched the lead further, with the five-eighth shrugging off three tackles to sprint the length of the field.
New Zealand finally got on the board when Shannon Mato barged across, but Chapman's third, bursting two tackles to race away, put Australia back in full control before Tamika Upton added a sixth before half-time.
Australia started strongly in the second half with only some desperate Kiwi defence keeping them at bay.
But it was a much tighter affair, with New Zealand's Mackenzie Wiki crossing in the dying seconds for the only try.