Rassie van der Dussen, Quinton De Cock and Keshav Maharaj powered South Africa to a 190-run victory against New Zealand in the 32nd match of the World Cup at Maharashtra Cricket Association Stadium in Pune on Wednesday.
South Africa's impressive total of 357-4 was anchored by De Kock's fourth century of the tournament, a stunning 114, and Van der Dussen's second century, a powerful 133.
In stark contrast to their previous near miss chasing 389 against Australia, New Zealand stumbled to 190 all out in Pune, still missing their injured captain Kane Williamson.
South Africa's pace attack, led by Marco Jansen's 3-31, wreaked havoc on New Zealand's top order, reducing them to 67-4.
Keshav Maharaj, the left-arm spinner, added to South Africa's dominance with 4-46, as New Zealand found themselves at 110-8.
Despite Glenn Phillips' defiant 60, the outcome of the match was never in doubt, and South Africa finally ended their run of five consecutive World Cup defeats to New Zealand since 1999.
This victory puts South Africa, who are aiming for their first ODI World Cup title, in a strong position to reach the semi-finals.
"Quinny played brilliantly," praised Van der Dussen, acknowledging De Kock's exceptional performance. "They (New Zealand) did well to keep a lid on us for a large part of the innings, but we knew if Quinny and I could take it deep, we could gain momentum."
New Zealand's third loss in the tournament jeopardises their chances of making the last four, dropping them to fourth in the table with eight points, just two ahead of Pakistan and Afghanistan, who still have a game in hand.
New Zealand captain Tom Latham remained positive, saying, "It's important we reflect on this one quickly and go into the next game with a positive mindset; you don't become a bad team overnight."
Latham's decision to field after winning the toss played into South Africa's strengths, a choice he defended by acknowledging De Kock and Van der Dussen's fantastic partnership.
De Kock, the left-handed opener, notched his 21st ODI century off 103 balls, featuring eight fours and three sixes. He reached the milestone with a towering six off Jimmy Neesham.
Feeling confident about his form, De Kock, who plans to retire from ODI cricket after this tournament, said, "My career is coming down to a finish; I'm trying to bat as much as I can."
De Kock had previously scored centuries against Sri Lanka, Australia, and Bangladesh in the tournament.
Van der Dussen continued the onslaught with 133 off 118 balls, including nine fours and five sixes, marking his second century of the World Cup and the sixth of his ODI career.
Tim Southee, who returned to the side, eventually dismissed both De Kock and Van der Dussen.
David Miller contributed a rapid 53 off just 30 balls, featuring four sixes, while Aiden Markram joined him at the end to launch a six off the final ball.
New Zealand had to employ seven bowlers after seamer Matt Henry suffered a hamstring injury, leaving the field during his sixth over.