Australian coach Lisa Alexander says their Quad Series clash with the Silver Ferns carries Commonwealth Games implications.
Silver Ferns player Maria Folau in action against the England Roses.
The unbeaten Diamonds can wrap up the four-nation tournament if they notch a sixth successive win over the New Zealanders in Johannesburg tonight.
However, a Silver Ferns win will throw the tournament open.
If they prevail by six goals or more New Zealand will retain the title, unless England record a decent win over South Africa in the subsequent final match.
However, Alexander was looking at the longer-term significance of the trans-Tasman clash, nearly two months out from the Commonwealth Games.
"There is no doubt that the winner of the netball Quad Series title will walk away with somewhat of an advantage over their opponents leading into the Commonwealth Games," Alexander said.
"It is important that we finish the series strongly, and continue to show constant improvement in each outing."
The series has proved challenging for both teams.
New Zealand went down 64-57 to England in extra time and worked hard to see off South Africa 51-46 in Johannesburg on Friday (NZT).
Australia notched four-goal wins over both opponents in London.
The Diamonds will be buoyed by the result a year ago to the day when they beat New Zealand 57-50 in the equivalent fixture in Durban.
However, Alexander is wary their arch-rivals will be motivated after losing the Constellation Cup series 4-0 in October.
"They will hit back hard," she said.
"We'll need to be ruthless against New Zealand and press home an advantage if given the opportunity. If we give them an inch, they'll take the full mile and run with it."
Silver Ferns counterpart Janine Southby confirmed her 12-strong squad for the Test, replacing shooter Maia Wilson with midcourter Whitney Souness in the only change from the Proteas clash.
Silver Ferns squad: Katrina Grant (capt), Kayla Cullen, Temalisi Fakahokotau, Maria Folau, Shannon Francois, Kelly Jury, Grace Kara, Bailey Mes, Te Paea Selby-Rickit, Samantha Sinclair, Whitney Souness, Jane Watson.