All Blacks brace for Rugby Champs decider against Boks

REACTION: New Zealand head coach Ian Foster says a showdown with the in-form Springboks is a challenge his All Blacks need following their 41-12 thumping of Argentina in Mendoza on Saturday in the Rugby Championship.

Foster predicted next Saturday's match against South Africa in Auckland will be 'a big one' after the Springboks were equally dominant in their 43-12 defeat of Australia in Pretoria earlier Saturday.

The clash at Auckland's Mount Smart looks set to determine the winners of the Rugby Championship, which is shortened to just three rounds of matches ahead of the World Cup starting in two months.

The Springboks fielded a weakened team in some positions against the Wallabies, choosing to fly a dozen players to New Zealand early in preparation to face the All Blacks.

Foster expects a blockbuster encounter.

"A big one - it's always big, we love playing South Africa," he said.

"They have taken 10, 11 or 12 players and put them over in Auckland early, so they have clearly got a plan, but our purpose in these first two weeks is to get this group together," he added.

"There is no better foe to play next week."

Foster said his team can't expect to make the same scintillating start against the Springboks as they did in Mendoza, where they crossed for three tries in the opening 12 minutes against Los Pumas.

However, with his team 31-0 ahead at the interval, he was pleased they were able to largely remain 'clinical' when Argentina showed some aggression in the second half.

"I thought we got a little bit over-ambitious in the final 15 [minutes] and tried to force things, which gave them some free shots at us," Foster added critically.

"It's a bit of a wake-up call - the first half was great, the second half is probably more of what's to come."

New Zealand flyhalf Damian McKenzie was among the standout performers after being named as a surprise starter ahead of Richie Mo'unga.

McKenzie may have done enough to earn another start next week, either as at flyhalf or fullback, in what he says will be a big occasion.

"They [Springboks] got off to a great start as well," he said.

"We'll enjoy this win, but it will be nice to get back home and play in front of our home crowd.

"It's going to be a challenge."