The Silver Ferns overcame a six-goal deficit to snatch a 54-53 win over the Diamonds in Sydney on Sunday, taking a 2-1 lead in the four-match Constellation Cup series.

Sparked by veterans Laura Langman and Maria Folau, New Zealand stunned the crowd of 13,497 at Qudos Bank Arena as they held their nerve better in the frantic closing stages.

Australian-born Ameliaranne Ekenasio made the winning shot with 20 seconds remaining after both teams made errors in a pressure-packed final five minutes.

"The last two minutes was sheer determination and grit," Ferns' coach Noeline Taurua said.

It was New Zealand's first Test win over the Diamonds in Australia in three years and it came after the Silver Ferns beat their trans-Tasman rivals in the World Cup final in England earlier this year.

The Silver Ferns can clinch just their second Constellation Cup series win in 10 attempts and their first in seven years if they win the final match in Perth next Sunday.

However a win by any margin will be enough for Australia to retain the Constellation Cup on percentage as their two losses were by a combined two goals while they won game two in Auckland by six.

"It would be massive and it's an opportunity for us after the World Cup," said player of the match Langman.

"We really do want to send this new-age Ferns into the future and have a little bit of dominance in our side."

Sunday's loss was another heartbreaker for the Diamonds after one-goal defeats in the Commonwealth Games and World Cup finals as well as the opening match of their current series.

We had our opportunities in the second quarter to really push on and we didn't and that shows the character of the Silver Ferns and the rivalry of the two teams," Diamonds coach Lisa Alexander said.

"They are still using their patient ball really, really smartly at the right times and we're still not able to get ball back in that situation."

Australia got an early jump, with slick passing and five straight goals setting up an 8-2 lead, with mid-courters Ash Brazill and Laura Scherian prominent.

New Zealand got back to within three by quarter-time.

"In the first quarter we were hanging on for dear life," Taurua said.

The Diamonds also started the second quarter well, again establishing a six-goal buffer, but their opposition reduced the deficit to one with a 5-0 run.

Alexander replaced goal attack Gretel Tippett, who had made all 12 of her shots, with Tegan Philip who missed her first two attempts.

Australia led 30-26 at the half but he Ferns made an 8-1 run to start the third to lead 34-31.

Five minutes into the quarter, Alexander made three changes with goalkeeper Sarah Klau, Philip and shooter Caitlin Thwaites replacing Courtney Bruce, Tippett and Caitlin Bassett.

Alexander said the changes worked but rued the absence through injury of mid-courter Paige Hadley.

Australia regained momentum, taking a 43-42 advantage into the final quarter only for New Zealand to hit back and lead 48-45.

The Diamonds led 52-50 with about five minutes to play but couldn't close it out.

Australian Associated Press