Kerr leads New Zealand to maiden Women's T20 World Cup triumph
Player of the Match Kerr top-scored with 43 as New Zealand posted an imposing 158-5 in their 20 overs before taking 3-24, and crucially picking up the key wickets of Laura Wolvaardt and Anneke Bosch, to restrict South Africa to 126-9 in their 20 overs.
It marked a sweet finish to skipper Sophie Devine's career.
The victory came 14 years after the White Ferns lost to Australia by just three runs in the 2010 final. They also lost to England in the 2009 championship match.
For South Africa it made for a double disappointment having lost last year's final to Australia in Cape Town.
After being put in to bat by South Africa captain Wolvaardt, the New Zealand openers began aggressively with Georgia Plimmer smashing two fours in the first over from Marizanne Kapp.
Plimmer fell for nine but Suzie Bates, playing in her 334th international, kept the scoreboard ticking over until she was bowled by Nonkululeko Mlaba for 32 from 31 balls.
When Devine was leg before to Nadine de Klerk on review, the innings appeared to be faltering but the arrival of Brooke Halliday lifted the tempo as she added 57 in seven overs with Kerr for the fourth wicket.
Halliday hit three boundaries in her 38 but was dismissed when she picked out Bosch on the midwicket boundary.
Kerr slammed back-to-back boundaries off Mlaba before finding Tazmin Brits to fall for 43 from 38 balls.
Maddy Green, however, maintained the momentum with 12 off six balls including the only six of the innings.
Wolvaardt (33) and Brits (17) got South Africa off to a roaring start bringing up the 50 in the seventh over before Brits attempted to hit Fran Jonas over long-on only to find the safe hands of Green lying in wait.
With Bosch struggling to get going, Wolvaardt showed her frustration by lashing the first ball of Kerr's second over to Bates at wide mid-off.
When a review concluded that Bosch had edged the last ball of the over to Isabella Gaze, South Africa had slumped to 64-3 and New Zealand were in command.
With the required run rate rising, South Africa's middle and lower order, who have barely batted in this tournament, struggled to get going with wickets tumbling at regular intervals.
Kerr took a catch to remove Nadine de Klerk and then claimed a third wicket when Bates, arguably the outstanding fielder at the tournament, took her third catch of the innings to remove Annerie Dercksen. She finished with a tournament-leading 15 wickets.
The last pair held out for the final over but could not prevent New Zealand from celebrating their first title.