The forward contest on Saturday was even New Zealand comfortably held the Pumas scrum and the difference between the teams, once again, was the quality of the All Blacks' finishing.
"They were wonderful conditions to play in and I'm really proud of the way the guys took their opportunities," McCaw said. "I think we defended really well. We didn't let them across the line until near the end and that shows the backbone of the team."
Argentina had too many turnovers 10 in the first half alone which contributed to New Zealand's 2-1 advantage in possession. But the decisive edge the All Blacks enjoyed was its ability to turn a handful of scoring chances into tries.
They did so twice in the first half, through Ben Smith and Israel Dagg to take a 20-3 lead after 24 minutes, which was only slightly reduced to 20-6 at halftime.
First Dagg made a break in the 11th minute from a pass from Malakai Fekitoa which unlocked the Pumas defense and when his angled run ended just short of the goal line, he turned the ball infield to Ben Smith who scored his 15th test try.
Smith returned Dagg's compliment in the 24th minute when he took the defense to breaking point on the right flank and fed Dagg for New Zealand's second try.
Flyhalf Barrett converted and finished the match with six goals from six attempts, shrugging off his inaccurate kicking performance when the teams last met in New Zealand two weeks ago. New Zealand won that match 28-9.
New Zealand made it clear throughout the match that its goal was to achieve the bonus point win which would cement their victory in the Championship ahead of the final round. They gave up chances to kick for goal throughout the second half, instead kicking for field position.
For the first 13 minutes of the second half, the Argentina defense held strong but it yielded when Barrett put in a chip kick from an attacking lineout which was caught on the fly by winger Julian Savea who touched down under the posts.
Referee Craig Joubert ruled, on the advice of the television match official, that Savea had been just ahead of the kicker and the try was disallowed. But three minutes later, Savea received a pass close to the left hand touch and barged through three defenders to score his 25th try in his 25th test.
The bonus-point try ranged from one end of the field to the other and featured an outstanding break by flanker Jerome Kaino and the involvement of Savea, whose final pass gave replacement scrumhalf T.J. Perenara his first test try.
"We wanted to win the game first and foremost," All Blacks coach Steve Hansen said. "If you go in there with an attitude that you want to score four tries then you're going in with the wrong attitude."
Argentina remained winless in the Rugby Championship but finished Saturday's match on a high note, with a try to replacement Horacio Agulla four minutes from fulltime.
"They played a great game," Argentina head coach Daniel Hourcade said. "The simple way they do things is awesome. They played the breakdown much better and made a difference there.
"Also, we could not make the most of our clean breaks. We paid our mistakes with points against."
____
New Zealand 34 (Ben Smith, Israel Dagg, Julian Savea, TJ Perenara tries; Beauden Barrett 4 conversions, 2 penalties), Argentina 13 (Horacio Agulla try; Nicolas Sanchez conversion, 2 penalties). HT: 20-6.