New Zealand won the Rugby Championship for the sixth time by beating Argentina 35-17 in Buenos Aires on Saturday as they put a stunning home defeat by South Africa behind them.

The All Blacks led 21-3 at half-time before a sell-out 50,000 crowd and scored first in the second half through substitute Patrick Tuipulotu.

Victory gave New Zealand an uncatchable seven-point advantage over South Africa ahead of their showdown in Pretoria next Saturday.

New Zealand have 21 points, South Africa 14, Argentina eight and Australia five with one round remaining in the southern hemisphere championship.

A shock 36-34 triumph in Wellington this month gave South Africa a glimmer of hope that they could overtake New Zealand and win the competition a first time.

But they failed to secure a bonus point as they ground out a 23-12 win over struggling Australia in Port Elizabeth earlier on Saturday.

That result left the All Blacks needing a win to secure the title and they outscored the Pumas by five tries to two to collect a bonus point as well.

No All Black was happier than fly-half Beauden Barrett who was successful with all four of his conversion attempts after missing four of six against the Springboks.

Argentina were first to score with star fly-half Nicolas Sanchez slotting an easy penalty after six minutes at the Estadio Jose Amalfitani.

But New Zealand reacted swiftly to falling behind and within two minutes were ahead as winger Rieko Ioane scored the first of his two tries.

Fellow winger Waisake Naholo came into midfield and played a key role in a move continued by Ben Smith before Ioane cut inside to score and Barrett converted.

Sonny Bill binned 

Sanchez seemed certain to cut the gap to a single point from a close-range penalty but, to the amazement of the crowd, fluffed it.

Naholo changed from creator to scorer on 17 minutes, stretching to dot the ball down on the line after the scrummaging weakness of the Pumas was laid bare.

Barrett added the extra points and the world champions were 14-3 ahead midway through the half.

Ioane struck again with 30 minutes gone, scoring a try that infuriated the home crowd.

Codie Taylor appeared to knock the head of Bautista Delguy, but big-screen replays showed the New Zealander had been pushed first by an Argentine.

French referee Mathieu Raynal correctly awarded a try and Barrett converted from the touchline.

In-form Delguy was forced to retire after the accidental blow and Sebastian Cancelliere took his place on the right wing.

Argentina finished the first half strongly after All Black Sonny Bill Williams was sin-binned, but could not translate territory and possession into points and the All Blacks led 21-3 at half-time.

Sanchez wasted an early second-half chance to reduce the deficit when his penalty intended for unmarked winger Matias Moroni fell short and into the welcome hands of Naholo instead.

The Pumas were being let down at the set pieces with the All Blacks making life miserable for the South Americans at the scrums.

Both teams scored two tries during the second half with Tuipulotu and Anton Lienert-Brown crossing for New Zealand and Barrett and Richie Mo'unga converting.

Tomas Cubelli and Emiliano Boffelli were the Argentine scorers and Sanchez added the conversions.