South Africa scrum-half Faf de Klerk warned his Rugby World Cup winners must be switched on for the full 80 minutes if they are to beat New Zealand in Auckland for the first time since 1937.

The All Blacks host South Africa on Saturday in a Rugby Championship clash at Mount Smart Stadium, two months before the World Cup kicks off.

Both teams recorded emphatic opening-round wins last Saturday. New Zealand thrashed Argentina 41-12 away and South Africa bulldozed Australia 43-12 in Pretoria.

However, it's 86 years and nine Tests since South Africa last won in Auckland, where they suffered a 57-0 drubbing to New Zealand in 2017.

That score remains the biggest margin in Tests between the rugby powerhouses.

De Klerk feels the Springboks have since won back respect from New Zealand's rugby public, especially after a thrilling 36-34 win over the All Blacks in Wellington in 2018, the year before South Africa lifted the World Cup. 

"Speaking to the fans over here and other players, I think there is a respect," he told reporters in Auckland.

"Look, a few years ago we weren't up to the standard in the way we played at all.

"Getting a lot of points put up against you isn't going to warrant respect.

"But the way the boys played last week shows there is something about us."

The scrum-half knows his side must be on their game against the All Blacks and a win for either team would put one hand on the Rugby Championship trophy.

De Klerk said that losing concentration even for a second can mean "you're probably going to end up behind the posts" having conceded points.

"If one or two guys just knock off for a moment, that's when they are going to attack you," he said.

De Klerk is one of the nine players in the starting South African team who sat out the win over Australia to fly to Auckland a week early in preparation.

He says the pressure is on to consolidate last week's win over the Wallabies by securing a rare victory in Auckland.

"I think they set the standard and we need to make sure we uphold that or outperform," he said.

"It's a squad effort.

"We have been training together for four weeks now, so we all know what to expect from each other."

It is unclear who will captain the Springboks after the father of their stand-in skipper Eben Etzebeth died earlier this week in South Africa.

An SA Rugby official told AFP the team's management will let Etzebeth decide whether he returns home or plays.

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