The All Blacks repelled a muscular Argentina challenge 33-15 in La Plata to set up a Test against South Africa next week to find the winners of the Rugby Championship.
Their fourth try in the last move of the game to wing Ben Smith handed New Zealand a bonus point, putting them on the front foot heading into the tournament-decider in Johannesburg next Sunday (NZT).
The unbeaten All Blacks are five points clear on the standings and need only to secure a bonus point against the Springboks - who earlier beat Australia 28-8 in Cape Town - to defend the inaugural Rugby Championship title they won last year.
South Africa, who have a superior points differential, must also score four tries in the process, something All Blacks coach Steve Hansen said could create opportunities for his own team.
"Our guys have already started talking about it so I don't think there will be any problem getting them up," he said.
Hansen's team scored three tries in the last 28 minutes against the Pumas, whose powerful forward pack dominated the first half in conditions made greasy by rain at the start of the Test.
The hosts trailed 11-9 at halftime and led 12-11 soon after the break when first five-eighth Nicolas Sanchez slotted the fourth of their five penalties.
However, opposite Aaron Cruden put the visitors back in front with his third penalty before tries to flanker Sam Cane and Smith in the 52nd and 56th minutes virtually made the game safe.
"They're a side that's getting better all the time. They're very, very good up front and they tried to play a bit of rugby today and played it quite well.
"We had to work for it and the bonus point at the end was exactly that, a big bonus for us."
The bonus point appeared beyond the visitors, particularly when wing Julian Savea botched a try after leading the chase from a grubber kick.
Savea, who scored New Zealand's only first half try through a brilliant 70m solo run, spilled the ball metres short of the line when trying to pick it up.
However, it didn't matter as Smith grabbed his second in the 79th minute after bulldozing over the top of Sanchez from close range to bag his ninth try in eight Tests this year.
The match was a far cry from last year's equivalent fixture when the All Blacks won 54-15.
The hosts dominated the early scrums and forced New Zealand into conceding a host of penalties both there and at the breakdown, where halfback Aaron Smith was constantly harassed.
Hansen said the scrum problem could attributed to a groin injury suffered by tighthead prop Owen Franks, who was replaced at halftime by the impressive Charlie Faumuina.
Among the best for the All Blacks were centre Conrad Smith and second five-eighth Ma'a Nonu, who were starting their 50th Test together. That equalled the world record as a midfield combination held by Ireland's Brian O'Driscoll and Gordon D'Arcy.
Conrad Smith said keeping their patience was the key to victory.
"They're a tough team to break down. Everyone's struggled to do it this year."
The Test was marred by a spectator shining a laser on the ball and surrounding area when Cruden was lining up his conversion attempt of Savea's try.
It mirrored an incident at the same venue last year when a laser was shone in Cruden's face.