It rubber stamped the vastly superior Opals' spot at next year's world championships after they won the series opener 98-48 in Porirua on Monday.
Tall Ferns coach Shawn Dennis described his young side's task as Everest-like before the series tipped off, and so it proved again as Australia's taller timber and superior skills shone through.
They led 27-15 at the first quarter break and 53-27 at halftime before the Ferns, with an average age of 21, competed better in the third quarter for a 14-19 deficit.
Both sides were missing a chunk of their Olympic lineups from last year but Opals giant Elizabeth Cambage was again a dominant figure, with 18 points and five rebounds before departing injured late in the match. She led the way with 22 points in game one.
Speedy guard Jessica Bibby led all scorers with 19 points, while Antonia Edmonson was the only Tall Fern in double figures with 11 points.
"I was really disappointed, I thought in the second half defensively we did a better job," Ferns coach Shawn Dennis told Fox Sports.
"I said before the start of the campaign we just can't get into an up and down game because we don't have the skill set to deal with that at the moment... I thought we could have kept the margin in the 30s which would have been a really big win for us given what happened the other night."
Dennis said his side lacked conditioning and missed too many open shots and freethrows, but would improve with the experience and the return of key players for their next campaign.
They achieved two minor goals of reducing the deficit from game one and keeping their opponents under 100 points.
Opals coach Carrie Graf was happy enough with her side's effort.
"We showed improvement in some areas we wanted to, and it was still a solid margin. It was a good battle even though it was a big margin."
Both teams were down a player from game one, with Ferns forward Pip Connell ruled out with an ankle injury and her Australian counterpart Rohanee Cox on crutches after suffering a knee injury.
Australia 97 (Jessica Bibby 19, Elizabeth Cambage 18, Elyse Penaluna 10) New Zealand 57 (Antonia Edmonson 11, Kate McMeeken-Ruscoe 8, Natalie Purcell 8, Suzie Bates 8, Lisa Wallbutton 8). Halftime: 53-27.
