Silver Ferns coach Janine Southby rolled the dice and injected impressive wing attack Whitney Souness and goal keeper Kelly Jury with the Proteas pressing, and it proved to be a masterstroke.
Maria Tutaia lines up a shot against South Africa.
A 20-12 third term by the Silver Ferns proved the difference against the world No.5 team, coached by former Australian mentor Norma Plummer.
Vice-captain Maria Tutaia stood tall as the Silver Ferns held out a plucky South Africa 63-56, notching 28 goals at 82 per cent.
"Having Souness and Jury out there, they are two players who have been on the radar for some time," 108 Test veteran Tutaia said.
"So for them to have the courage to put them on in such a pressure match, it took some balls to put them out there."
New Zealand's Bailey Mes led the attack with 35 goals, missing just one shot.
It was still a huge effort by South Africa who were thrashed 70-39 the last time they met in February.
The Silver Ferns had won by an average of 31 goals in their past six games since 2012.
South Africa have beaten New Zealand just once in 29 previous contests when Kiwi great Irene van Dyk was representing the Proteas in 1995.
The win was an important first step toward the 2018 Gold Coast Commonwealth Games for New Zealand.
After the Quad Series, the Silver Ferns tackle a three-test home series against England next month.
Then a new 12-strong squad will be named for four Constellation Cup Tests against Australia in October that will effectively be their Games team.
"It was a pass mark overall," Southby said.
"There was some great stuff in attack but defensively I think we have a lot of work to do."
The eight-day Quad Series is expected to be decided when Australia meet New Zealand in Invercargill on September 3.
Meanwhile, Australia held out England 54-50 in the opening Quad Series clash.
The series next moves to Canberra on Wednesday before concluding in New Zealand.