New Zealand All Blacks coach Steve Hansen believes his team's Rugby Championship match against Argentina on Saturday will be the "defining moment" of the 2013 Rugby Championship.
The tournament leaders and defending champions have a four-point lead over South Africa ahead of their Test at the Estadio Ciudad de La Plata, 58 kilometres south-east of Buenos Aires.
And with a final-round showdown against the Springboks to come in Johannesburg on October 5, the All Blacks coach wants a bonus-point victory this weekend.
That would ensure world champions New Zealand remain at least four points ahead of their greatest rivals in the southern hemisphere title race.
South Africa are favoured to defeat Australia earlier Saturday, but the expected wet Cape Town conditions could make it difficult to achieve a four-try bonus point.
"This is a huge challenge for us," said Hansen as he looked ahead to a Test at a ground where the All Blacks sparkled in a 54-15 triumph last season.
"It will be the defining moment of the Rugby Championship this year. If we are to have a chance of retaining the title, we have got to win this game.
"We must try to win it well," he added ominously as New Zealand seek to maintain a 28-year dominance over the Pumas.
The countries have clashed 17 times and the All Blacks have won all bar a 21-21 draw in Buenos Aires the second time they squared off.
Hansen does not foresee a repeat of the 2012 try-fest when the All Blacks recovered from a sluggish start to pound the Pumas into submission.
"We caught them unawares last year and we will not enjoy that luxury Saturday," admitted the former Wales coach.
"Argentina are a better side this year than last, although I don't think they have found the game they want to play yet.
"We must pay them a huge amount of respect and the ideal way to do that is to prepare the best we possibly can."
Hansen has made two changes from the side that started in a fiery 29-15 mid-September triumph over South Africa at Eden Park in Auckland.
Fly-half Aaron Cruden replaces injured Dan Carter and experienced hooker Andrew Hore is recalled with Dane Coles dropping out of the matchday 23.
"Everyone in this team has earned the right to be there," said Hansen, who believes La Plata is not the place to experiment with right-wing Ben Smith at centre.
While New Zealand eye a second successive Rugby Championship crown, Argentina are seeking a first victory in the competition after one draw and nine losses, including four this season.
While they fell 28-13 in the wind and rain of Hamilton this month, they did prevent the All Blacks claiming a four-try bonus point.
That performance and a single-point loss in Australia two weeks ago offer hope to coach Santiago Phelan and a team skippered by flank Juan Martin Fernandez Lobbe.
The inspirational loose forward was sorely missed in Soweto during August as the nine-try Springboks romped to a 73-13 victory.
"We are going from low to high this season, improving game by game," said former Pumas loose forward Phelan.
"The pressure of facing the top three teams in the world is extreme, but we are slowly but surely adapting to the challenge.
"New Zealand are a complete team -- the best in the world. They play with such speed and intensity. We have prepared well and hope for the best."
Phelan has made six changes to the side that started in Perth, where the Pumas scored 10 unanswered second-half points and had could have won.
In come right-wing Lucas Gonzalez Amorosino, centres Marcelo Bosch and Santiago Fernandez,scrum-half Martin Landajo, hooker Eusebio Guinazu and lock Patricio Albacete.
Horacio Agulla, veteran Felipe Contepomi, Tomas Cubelli and Agustin Creevy drop to the bench while there are no matchday places for Gonzalo Tiesi and Manuel Carizza.