The All Blacks proved once again why they are the top-ranked rugby team in the world on Saturday, pounding Argentina and securing their third straight Rugby Championship.

New Zealand clinched the title with a game to spare, beating the Pumas 34-14 at Estadio Ciudad de La Plata.

The All Blacks stormed the Argentines in the first half, building up a 20-6 lead through 40 minutes that they would not relinquish.

Beauden Barrett did much of the first half damage, kicking two penalty goals and two conversions to pad a Ben Smith try.

Julian Savea and TJ Perenara would count in the second half to complete a convincing win for the All Blacks, who held the Argentines entirely to penalties up until Horacio Agulla's 78th-minute try.

The victory extends the All Blacks' unbeaten run at the tournament to an impressive 17 matches.

They conclude their Championship slate with a visit to Johannesburg to play the Springboks next weekend.

The Springboks all but assured themselves of second place in the tournament this weekend with a comeback 28-10 victory over the Wallabies that saw them score 23 unanswered second half points.