The Australian Diamonds have all but won their sixth Constellation Cup in seven years after thumping New Zealand 62-50 in Auckland.

The 12-point victory gives the Diamonds a 2-1 lead in the four-game netball Test series and a near-insurmountable 22-goal advantage.

Only the most extraordinary of Diamonds collapses in the final Test in Invercargill on Thursday would see the Silver Ferns lift the trophy for the second time.

Star goal shooter Caitlin Bassett was near-unplayable for the visitors, netting a personal best 55 goals from 64 attempts as her midcourters lofted pass after pass into her path.

Silver Ferns boss Janine Southby said her team simply didn’t have enough urgency to stem the flow of ball towards the 193cm Bassett.

On-court complacency had cost them dearly after their surprise two-point win in Launceston on Wednesday.

“They really stepped up the pressure on us on the body and I don’t think we could cope with that at times, that takes a bit of a toll,” Southby said.

“They were letting the ball go in and they really improved their passing accuracy.”

There was little to separate the world’s best two netball sides in the first quarter, with both outfits looking sharp in the shooting circle.

Bassett duels with Anna Harrison of New Zealand.

However, the 13-13 first-quarter score quickly blew out as Bassett put her foot down, aided by the also tall goal attack Gretel Tippett and wing attack Madi Robinson.

Bassett nailed 13 from 14 in the second quarter, 15 from 16 in the third and 16 from 19 in the fourth to put the match to bed.

“They did look into her a lot earlier than they did the other night and just let it go,” Silver Ferns skipper and goal defence Katrina Grant said.

“They backed themselves and threw it in and it worked for them, we needed to adjust earlier but didn’t.”

Diamonds boss Lisa Alexander, meanwhile, lauded her charges for their display after a disjointed performance in Launceston.

Gabi Simpson looks to deny New Zealand’s Shannon Francois .

Their fight and intensity had returned despite a short turnaround, and they put forward a more methodical offensive display.

Bassett had carried out her game plan to the letter by keeping a cool head and out-manoeuvring Kiwi goal keeper Anna Harrison.

“She’s getting used to being more focused and having more physical pressure on her, even in this last series I observe that,” Alexander said.

“What happened in Launceston is that she let it get to her, instead of staying strong mentally.”

-AAP