A late try from right wing Ben Smith helped New Zealand to a 33-15 bonus-point win over Argentina on Saturday.
That critical fourth try puts the All Blacks five points clear of the Springboks ahead of the two team's meeting at Ellis Park in Johannesburg next week.
South Africa know they must beat New Zealand with four tries or more whilst also denying their hosts a losing bonus-point. It is a tough ask.
It had looked like being an extremely tough night for the All Blacks though when the Pumas enjoyed the better of the opening sparring. New Zealand were struggling to get their hands on the ball.
Marcelo Bosch had an opportunity to draw first blood when his 55-metre penalty attempt sailed well wide. However, Argentina weren't to be denied in the eighth minute as Nicolas Sanchez sent over three points following Andrew Hore's high tackle. It was a lead they richly deserved.
New Zealand responded five minutes later as Argentina failed to release the tackler so up stepped Aaron Cruden — in ahead of the Beauden Barrett and the injured Dan Carter — before the lead was Argentina's again in the sixteenth minute. Fly-half Sanchez was looking in good shape from the kicking tee at close range.
With a quarter of the game gone came another plus point for the Pumas — and in fact the watching Springboks — as Juan Figallo dominated Tony Woodcock at scrum time. In fact Marco Ayerza would do the same to Owen Franks later in the half — after Sanchez's first miss.
But as is New Zealand's wont, they struck when given a sniff. It was Julian Savea who profited as he snaffled up the loose ball before racing in for the game's first try. Unfortunately for the visitors, Cruden was off-target. Unfortunately for rugby, the fan with a laser was not.
Cruden did extend the advantage to five points just before the half-hour when the Pumas joined a ruck incorrectly, but then came Leicester prop Ayerza's moment at the set-piece. Net result being that Sanchez had brought his side back to a 9-11 deficit at the break.
An indication of the Pumas' scrum dominance could have been signalled by Franks being replaced at half-time by Charlie Faumuina. But worryingly for New Zealand was the sight of the replacement prop being pinged at his first set-piece. Bosch was successful this time.
11-12 didn't last long though as Cruden landed three points of his own before the All Blacks found top gear. Their second try arrived following solid tight work from the pack before the ball was shipped wide by Cruden and Ma'a Nonu to the waiting Sam Cane on the left wing.
Two became three in a short space of time as New Zealand had turned the screw at Estadio Ciudad de La Plata. Their next score en route to the bonus-point saw Nonu again act as the provider, sending off a lovely pop pass to wing Smith off the shoulder in midfield. The winger raced over from 35 metres making for a simple conversion for Cruden.
New Zealand were now in full control of the Rugby Championship game as the Pumas' fitness combined with the superior mental strength of the All Blacks came to the fore.
And just when it looked like the fourth try was not coming, up stepped wing Smith as he barged over the would be tackler en route to the uprights for the vital bonus point.
Man of the match: Constantly looking for work while being smart when in possession, Ben Smith takes this ahead of namesake Conrad due to his two scores. Meanwhile Ma'a Nonu impressed at inside centre, as did the Pumas props Juan Figallo and Marcos Ayerza.
Moment of the match: It has to be Ma'a Nonu's double pump pass for Ben Smith's first try. The pass was a beaut and came after Nonu had driven back an Argentine in an earlier phase. He really is a different player from Super Rugby when he pulls on that Black jersey.
Villain of the match: The fan(s) with a laser pen.
The scorers:
For Argentina:
Pen: Sanchez 4, Bosch
For New Zealand:
Tries: Savea, Cane, B Smith 2
Con: Cruden, Barrett
Pen: Cruden 3
Argentina: 15 Juan Martín Hernandez, 14 Lucas Gonzalez Amorosino, 13 Marcelo Bosch, 12 Santiago Ferníndez, 11 Juan Imhoff, 10 Nicolís Sanchez, 9 Martin Landajo, 8 Juan Manuel Leguizamon, 7 Pablo Matera, 6 Juan Martín Ferníndez Lobbe (captain), 5 Patricio Albacete, 4 Julio Farias Cabello, 3 Juan Figallo, 2 Eusebio Guiñazú, 1 Marcos Ayerza.
Replacements: 16 Agustin Creevy, 17 Nahuel Lobo, 18 Juan Pablo Orlandi, 19 Mariano Galarza, 20 Benjamín Macome, 21 Tomas Cubelli, 22 Felipe Contepomi, 23 Horacio Agulla.
New Zealand: 15 Israel Dagg, 14 Ben Smith, 13 Conrad Smith, 12 Ma'a Nonu, 11 Julian Savea, 10 Aaron Cruden, 9 Aaron Smith, 8 Kieran Read, 7 Sam Cane, 6 Liam Messam, 5 Sam Whitelock, 4 Brodie Retallick, 3 Owen Franks, 2 Andrew Hore, 1 Tony Woodcock.
Replacements: 16 Kevin Mealamu, 17 Wyatt Crockett, 18 Charlie Faumuina, 19 Jeremy Thrush, 20 Steven Luatua, 21 Tawera Kerr-Barlow, 22 Beauden Barrett, 23 Charlie Piutau.
Referee: Jaco Peyper
Assistant referees: Nigel Owens (Wales), Pascal Gauzí¨re (France)
Television match official: Graham Hughes (England)
The humbling of a half-time team-talk on the field in front of a gleeful Newlands crowd underlined how far Australia have fallen — McKenzie overseeing his fourth loss since taking over as head coach.
The Springbok hooker, the visitors' first try scorer at Eden Park, was shown two yellow cards within the opening 45 minutes by referee Romain Poite.
The win wasn't pretty but the hosts will take it, as it's the first under new coach Ewen McKenzie, and ends a four-match winless streak which stretches back to their loss in the series decider to the British and Irish Lions in July.
Victory was tinged with concern, however, for the All Blacks as Richie McCaw suffered a knee injury that puts him in doubt to take on the Springboks.
The results means the Springboks will head to New Zealand next week at the top of the standings, one point above the All Blacks by virtue of a four-try bonus point.
The Springboks were unable to produce the same clinical finishing that saw them rack up so many point last weekend, sucked into a breakdown battle that they often lost until Steyn's boot prevailed in the closing stages.
The Wallabies were more competitive than last weekend's encounter in Sydney but the All Blacks made better use of their opportunities which sealed their victory.
Quite simply, the Boks were dominant and had this result sewn up after half-an-hour before the floodgates opened and the Pumas shut down.
The All Blacks kept hold of the lead for the majority of the match as both teams played with great width and endeavour throughout, a classic performance featuring eight tries in total, including a hat-trick for Ben Smith and a length-of-the-field classic from Will Genia.
Australia were simply unable to live with the Lions in the second half, with the tourists unleashing a triple punch of tries from Jonathan Sexton, George North and Jamie Roberts — inspired by the brilliance of Leigh Halfpenny.
Adam Ashley-Cooper's 76th minute sucker-punch broke the Lions hearts, with Leigh Halfpenny's injury-time penalty attempt dropping short of the posts.
The result means Heyneke Meyer's team claim the silverware at the end of the four-nation quadrangular series involving Italy and Scotland, but more importantly, they bounced back from an under-whelming display in Nelspruit a week ago.
The result leaves Italy win-less on their three-game tour of South Africa having already lost to Samoa and the Springboks.
The replacement was unsuccessful off the tee as an Australian outfit decimated by injuries almost pulled off a famous victory against the tourists.
The result is New Zealand's seventh consecutive win over the French, who were once again held try-less, but the result hung in the balance right up to the dying minutes.
The Pacific islanders scored four tries against the Americans' one during the game in Nagoya, central Japan.
The loss is Canada's first in the 2013 competition and means that either Fiji or Tonga, who face each other on Sunday, June 23, can win the title.
Tonga, who fell 36-27 in Ontario last Saturday to unbeaten Canada, were without three players suspended by the IRB as a result of last week's match — full-back David Halaifonua, prop Eddie 'Aholelei and centre Siale Piutau.