New Zealand won the Rugby Championship for an eighth time on Saturday after rivals South Africa failed to secure a bonus point and a wide winning margin when beating Argentina 38-21 in Durban.
The Springboks needed a bonus point in the final match of the tournament and victory by at least 39 points to pip the All Blacks for first place.
Earlier on Saturday, New Zealand thrashed Australia 40-14 in Auckland for a bonus-point triumph that took them to 19 points in the six-round Championship.
Rugby World Cup title-holders South Africa finished with 18 points, Australia 10 and Argentina nine in the most exciting southern hemisphere tournament since its launch 10 years ago.
New Zealand have regularly won the Championship with several matches to spare, but this season it went down to the wire.
The All Blacks were the victims of the biggest shock, losing at home to Argentina for the first time.
"We never take a win for granted," said South Africa captain and flanker Siya Kolisi.
"It's always an honour to get a win against a team like Argentina. We had a plan and we got near our goal.
"It was going well (when leading 17-0) and we wanted to score again but they scored just before half-time and that set us back a little bit.
"They started well in the second half and then our discipline let us down at times and we had two yellow cards.
"The biggest thing (so far) from this season was that even in the games we lost we created so many chances. Our game plan is working but we just don't take the opportunities."
PUMAS HIT BACK
When veteran Francois Steyn, making his first start at flyhalf since 2008, slotted a penalty from his own half just before half-time South Africa led 17-0 before a sell-out 45 982 crowd.
But the Pumas hit back almost immediately with scrumhalf Gonzalo Bertranou scoring and winger Emiliano Boffelli converted to cut the deficit to 17-7 at the break.
As they did last weekend when losing 36-20 at home to South Africa, Argentina were a much improved team from the restart and flanker Juan Martin Gonzalez scored a try Boffelli converted.
It was no longer a question of whether the Springboks could overtake the All Blacks, but whether they could weather the Argentine storm and win the match.
They succeeded thanks to two penalty tries as Australian referee Damon Murphy repeatedly flashed his yellow card -- sending four Argentines and two South Africans to the sin bin.
A try by recalled centre Matias Moroni which Boffelli converted left South Africa leading only 24-21 with 11 minutes remaining.
But the second penalty try gave the home side breathing space and replacement back Kurt-Lee Arendse crossed the line in added time and the final whistle sounded after Steyn converted.
Steyn, a Rugby World Cup winner in 2007 and 2019, gave a flawless goal-kicking performance, slotting three conversions and a penalty from his four shots at the posts.
Number 8 Jasper Wiese, who was voted man of the match, and captain and Kolisi scored tries for South Africa in the opening half.
Next up for the Springboks is a challenging November tour of Europe in which they will face Ireland, France, Italy and England on consecutive Saturdays.