Finn Allen smashed the fastest T20 World Cup hundred, from just 33 balls, as New Zealand cruised into the final after ending South Africa's unbeaten run in the tournament with an astonishing nine-wicket thrashing in Kolkata.
South Africa had won their first seven matches at this year's competition, including a seven-wicket rout of New Zealand in their first-round meeting on Valentine's Day as they extended their head-to-head against the Kiwis to 5-0 in T20 World Cups at that point.
But Aiden Markram's side missed out on successive finals - they finished runners-up to India in the Caribbean in 2024 - after New Zealand romped to a target of 170 in just 12.5 overs off the back of a rip-roaring opening stand of 117 from 55 balls between Allen (100no off 33) and Tim Seifert (58 off 33) at Eden Gardens.
The carnage included Allen crunching five boundaries in a row off Corbin Bosch in the sixth over as the Black Caps cantered to 84-0 in the powerplay and then five more on the trot off Marco Jansen in the 13th, with the match-winning four taking him to three figures.
West Indies legend Chris Gayle held the previous record for the fastest Men's T20 World Cup century, a 47-ball effort against England a decade ago, but Allen, who hit 10 fours and eight sixes, obliterated that.
Jansen's 55no off 30 balls, which rallied South Africa from 77-5 to 169-8, came in vain as New Zealand advanced to Sunday's showpiece in Ahmedabad and ensured their opponents' wait for a first World Cup title goes on.
The Black Caps will face the winners of Thursday's Mumbai semi-final between England and India, both of whom have won the T20 World Cup twice before.
New Zealand's best result is runners-up to Australia in 2021 but they now have a chance to better that after beating South Africa for the fourth time in succession in an ICC knockout match, after the 2011 50-over World Cup quarter-final, 2015 semi-final in the same event and 2025 Champions Trophy semi.
The Kiwis enjoyed a dream start after winning the toss against South Africa, with spinner Cole McConchie (2-9) striking from successive balls in the second over - Quinton de Kock (10) caught at mid-on, Ryan Rickelton (0) at short third.
Markram (18) and David Miller (6) were unable to properly punish their opponents after both were dropped on three, holing out in the deep off Rachin Ravindra (2-29), while Dewald Brevis sliced to cover after smoking two sixes in his 34 off 27 deliveries.
Jansen and Tristan Stubbs (29 off 24) revived the innings with a sixth-wicket stand of 73 from 48 balls and the former, who clubbed five maximums in his 27-ball, second T20I fifty, ended not out after Matt Henry's twin strikes of Bosch (2) and Kagiso Rabada (0) in the final over.
Stubbs had earlier been castled by Lockie Ferguson (1-29).
South Africa needed early wickets to give New Zealand jitters but a chance was blown in the second over with De Kock failing to catch a Seifert top edge after rushing from his wicketkeeping spot to fine leg and telling fielder Brevis to stay out of the way.
Brevis was arguably in a better position to claim the ball.
Seifert, on 11 at the time of De Kock's non-catch, nailed Jansen for back-to-back boundaries in an 18-run third over and when Allen went berserk in Bosch's 22-run sixth, the game looked over already.
Just under seven overs later it was done - Seifert, bowled by Rabada, was the only wicket to fall - keeping alive the prospect of another New Zealand vs England World Cup final, seven years after their 50-over epic at Lords.
New Zealand captain Mitchell Santner:
"It was special to watch [Allen and Seifert]. We were very happy with a target of 170 going into our innings, but you never know.
"They went out there, played their game and took it on, which was cool to see. And then Finn carried on - 33 balls for a ton is not too bad!"
South Africa captain Aiden Markram:
"To get up to 170 was a great effort, to be fair, and at the halfway point we felt like we had a sniff. But then someone plays an innings like that [Allen's].
"Massive credit to his knock and Tim Seifert's knock, to kill the game as early as they did. Unfortunately it was just a bad night for us tonight."
Player of the match, New Zealand's Finn Allen:
"We wanted to try and put them on the back foot early. When Tim [Seifert] is going like that, it makes it easy for me... I can just watch and hit it when it's in my area, and we got off to an absolute flier.
"It's easy in a semi-final to stay up for the fight - it was a huge game for us - and we enjoyed it out there together.
"You take the positives from this game, celebrate that little moment of success and then we've got a final to win on Sunday. We look forward to that."
Watch England vs India in the second T20 World Cup semi-final, at Wankhede Stadium in Mumbai, live on Your Site Cricket and Your Site Main Event from 1pm, Thursday (1.30pm first ball).
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Semi-finals
Wednesday March 4
Thursday March 5
Final
Sunday March 8
