Damian Willemse insists the Springboks must sharpen their edge in attack if they want to topple the All Blacks in Wellington on Saturday.

The utility back, who will start a Test match in the No 12 jersey for the first time, admitted that South Africa's inability to convert pressure into points cost them dearly in the opening Test at Eden Park.

"We've got to make sure we're clinical," Willemse told the media in Wellington.

"Not like last week where we had about ten entries into the All Black 22 and didn't capitalise on many of them, so that's been a large part of our focus this week."

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The Boks lost momentum in Auckland despite creating a host of scoring opportunities, and Willemse believes their approach in Wellington must be far more ruthless.

"For us, we're focused on going out there on Saturday and making sure we can play positively and get the victory," he explained.

"Expressing yourself isn't always playing flashy rugby. For us it's about nailing our roles, and if an opportunity presents itself, we take it. That's expressing ourselves."

With the Rugby Championship on the line, Willemse stressed that the Springboks are zeroing in on the "small moments" that decide Test matches.

"We're really focused on the micro details, being dialled in for every chance that presents itself," he added.