Conrad Smith believes Saturday's test against South Africa could be the All Blacks' biggest challenge since the 2011 World Cup final.
Both teams are undefeated in the Rugby Championship heading into their clash, with the Springboks sitting on top of the table after their bonus-point 38-12 win over Australia.
The Eden Park match could mark the defining point in the tournament; a South African victory would take them a long way towards their first Rugby Championship or Tri-Nations title since 2009.
"We're certainly viewing it as the biggest challenge probably since the World Cup for us, so we're prepared for a big game," the veteran centre said.
"We're up against a team that's coming over with form, it didn't take much to look at that Springbok performance in the weeks previous to know they're playing some really good footy and if we're not up to the mark then we're going to come second."
The Boks demolished a shambolic Australia in Brisbane on Saturday and looked polished and hungry.
Captain Jean de Villiers is in outstanding form and the All Blacks know the 91-test centre poses a big threat.
"He's looking good and getting around the park well," Smith said.
With nine wins on the trot, the Springboks are building nicely towards Eden Park, where the All Blacks remain unbeaten since 1994.
After winning in Brisbane for the first time, the Boks are in a hoodoo-busting mood.
Despite a below-par performance against Argentina in difficult conditions in Hamilton, the All Blacks are also tracking well.
"We were keen to play and we didn't really want the rain to stop us, but it probably took us half a game to realise that the conditions were that bad that we just had to sacrifice some of the way we wanted to play and be smart," Smith said.
He is hoping the weather stays fine in Auckland and the Eden Park pitch is hard so the backs can be unleashed.
South Africa would no doubt welcome a spot of wet weather to slow the All Blacks down, as they try to smash them up front and at the breakdown. The massive Bok pack denied Australia quality possession at set-piece and the tackle-ball area, something they will hope to repeat on Saturday.