Kane Williamson grabbed his second century of the match as New Zealand took complete control of the first Test on day three against the Proteas.

Williamson was dismissed for a quick 109 as the home team scored 179-4 in their second innings at Mount Maunganui, extending their overall lead to 528 runs before stumps.

Daryl Mitchell was at the crease on 11 and Tom Blundell on five, with the Black Caps hoping to declare early on Wednesday, with South Africa facing a daunting target on a deteriorating Bay Oval pitch.

The weakened Proteas were bowled for 162 shortly before tea in response to New Zealand’s 511 in the first innings.

The follow-on was not enforced, allowing the world’s top batsman, Williamson, to add another massive score to his 118 in the first innings.

It was the former captain’s 31st Test century, but it was the first time he had scored three figures twice in the same match.

The 34-year-old batted aggressively from the start, hitting 12 fours and a six in 132 balls to signal New Zealand’s determination before being stumped by Proteas captain Neil Brand.

Williamson, like in the earlier innings, survived a dropped catch in the outfield, this time by Edward Moore, who was on 61.

Moore reacted in the following over by capturing Devon Conway for 29 off captain Neil Brand’s bowling, bringing an end to his 92-run stand with Williamson after opener Tom Latham went cheaply.

Rachin Ravindra, the first innings double-centurion, was out for 12 shortly afterward, caught off the spin of Brand, who took six wickets.

South Africa’s second-string status was revealed when they lost their last six wickets for 82 runs on Tuesday.

The highest score was 45 by Keegan Petersen, who is the most experienced batsman in the side after most first-choice players stayed behind to compete in a domestic Twenty20 tournament.

Petersen lost his overnight companion David Bedingham for 32 when he attempted to hook seamer Matt Henry, and Ruan de Swardt followed with a second-ball duck in the same over.

Wicketkeeper Clyde Fortuin, one of six Proteas debutants, departed for nine just before the tourists went to lunch on 129-7.

The tail was easily tied up, with Henry scoring 3-31 and Mitchell Santner finishing 3-34 thanks to spin-friendly conditions.