The White Ferns are now just one game away from progressing to the semi-finals of the Women's World Twenty20, having beaten South Africa at Galle International Stadium in Sri Lanka.
Chasing 152 for victory, South Africa were restricted to 129 for nine from their twenty overs, giving the White Ferns an important 22 run victory.
The target seemed out of reach from the outset for South Africa, who lost two early wickets only 15 runs into their innings.
That brought Alison Hodgkinson and Susan Benade together in the middle and between them they temporarily took the momentum away from New Zealand.
Having claimed two wickets for six runs in her first two overs, Erin Bermingham was then punished in her third with 15 runs coming from it. Benade in particular was the aggressor smashing a six and a four within the first three deliveries.
At 53 for two after 8.3 overs South Africa were right in the game, until Benade's rapid innings of 24 came to an end. Her 16 ball tenure concluded when she was caught by Morna Nielsen off the bowling of Nicola Browne.
Hodgkinson remained in the middle, but fell for 31 in the 12th over, effectively ending South Africa's chances.
A collapse followed her dismissal, as the White Ferns began to strike regularly. It soon became obvious that the result was never in doubt, despite a valiant effort from number eight Dane van Niekerk who ended the innings unbeaten on 34.
Browne was formidable with the ball and finished with figures of three for 13, while Sophie Devine and Bermingham picked up two apiece.
Earlier the White Ferns had overcome a slow start to post a very competitive total of 151 for five.
Openers Suzie Bates (14) and Amy Satterthwaite (2) were out early, leaving New Zealand 24 for two.
The two new batsmen Devine and Frances Mackay initially struggled to get on top of the South African bowling attack, but soon found their rhythm and punished them with a 94 run stand for the third wicket.
Devine struck three sixes and five fours in her 59 from 46, while Frances Mackay fell just one run short of her half century with 49 from 40.
Both Sara McGlashan (9) and Browne (9*) finished off the innings with quick cameos, as the White Ferns surpassed the 150 mark.
Benade was the best of the South African bowlers, picking up figures of two for 15 from four overs.
The White Ferns will next play host nation Sri Lanka on Sunday, where a win will book them a ticket to the semi-finals.