They had the All Blacks in panic mode - something rarely seen and as they cranked the pressure, they made another huge breakthrough when Conrad Smith was yellow carded for diving into a ruck to kill the ball.
It was scarcely believable - the two most experienced and normally calm players within the All Blacks were both yellow-carded for rash acts.
Reduced to 13 men and faced with a rampant Pumas side and a huge crowd that were mostly backing Argentina to pull off a huge upset the day after Japan had beaten South Africa, there were more than a few Kiwis who were losing hope.
It looked like the All Blacks were imploding, that they were going to lose their first pool game in World Cup history.
Kieran Read and Carter pulled things together, though, and strangely, reduced to 13 men, the All Blacks lifted their performance. They managed to land a penalty before the break and once Smith and McCaw returned, the All Blacks eventually managed to break them in the final quarter - scoring two tries through Aaron Smith and Sam Cane to win 26-16.
The only other time the undefeated run has been in danger was during the semifinal of the World Cup. That, in truth, has been the only genuine nail-biter in the sequence. That has been the only game of the 17 so far where the outcome was still in doubt in the last few minutes.
Argentina, while rampant in the first half in London, had been subdued by the last five minutes. The Boks, though, despite playing so little rugby, refused to make things easy.
For the first and only time of the tournament, the rain fell steadily at Twickenham and try as they did, the All Blacks could never push more than two points ahead of the Boks.
New Zealand led 20-18 in the last five minutes and needed a miraculous Sam Whitelock lineout steal to keep them safe.
Other than that, the All Blacks have wiped the floor with about every other side they have encountered since they beat Australia at Eden Park last year and that is probably what makes the last 14 months so impressive. The All Blacks have not only won, they have won emphatically.
This year they are averaging five tries per game and their narrowest margin of victory has been 14 points in the second test against Wales.
That's a close game - a 14-point victory and a run that nearly ended at two is now on the verge of reaching a world record 18.
The run so far
1. Aug 15, Eden Park: All Blacks 41 Australia 13
World Cup
2. Sept 21, Wembley, London: All Blacks 26 Argentina 16
3. Sept 25, Olympic Stadium, London: All Blacks 58 Namibia 14
4. Oct 3, Millennium Stadium, Cardiff: All Blacks 43 Georgia 10
5. Oct 10, St James' Park, Newcastle: All Blacks 47 Tonga 9
6. Oct 18, Millennium Stadium, Cardiff: All Blacks 62 France 13
7. Oct 25, Twickenham, London: All Blacks 20 South Africa 18
8. Nov 1, Twickenham, London: All Blacks 34 Australia 17
2016
9.Jun 1, Eden Park: All Blacks 39 Wales 21
10. Jun 18, Westpac Stadium: All Blacks 36 Wales 22
11. Jun 25, Forsyth Barr Stadium: All Blacks 46 Wales 6
12. Aug 20, ANZ Stadium, Sydney: Australia 8 All Blacks 42
13. Aug 27, Westpac Stadium: All Blacks 29 Australia 9
14. Sept 10, Waikato Stadium: All Blacks 57 Argentina 22
15. Sept 17, AMI Stadium: All Blacks 41 South Africa 13
16. Oct 2, Estadio Jose Amalfitani, Buenos Aires: Argentina 17 All Blacks 36
17. Oct 9, Kings Park, Durban: South Africa 15 All Blacks 57