Proteas stumble in Hamilton

The Black Caps have the smell of blood in their nostrils after a South African second-innings batting collapse has handed them a winnable position for the final day of their Test decider in Hamilton.

Notching a 175-run lead after being bowled out for 489 on Tuesday, New Zealand went on to limit the Proteas to 5-80 at stumps on day four and decimate their opponent's upper order.

Openers Dean Elgar and Theunis de Bruyn fell for just 17 runs combined, continuing on from their poor first-innings showing of five, while Hashim Amla fell soon after for 19.

The loss of de Bruyn was particularly farcical, as Amla looked for a quick single and bundled into his batting partner, handing Kane Williamson the simplest of run-outs.

JP Duminy and Temba Bavuma meekly followed suit for 13 and one run respectively as the South African batting line-up self-destructed.

But all is not lost for the Proteas, with talisman Faf du Plessis and Quinton de Kock still at the crease and determined to secure a series-winning drawn Test.

Skipper du Plessis and wicketkeeper-batsman de Kock both snared 15 by stumps, sending the Proteas into the final day with a 95-run deficit.

Their miserable late-session batting performance stands in stark contrast to New Zealand's efforts earlier in the day, with Williamson's elegant ton and a handy half-century from Colin de Grandhomme putting their side on the front foot.

Williamson, starting Tuesday on an unbeaten 148, quickly passed the 150 mark before eventually being snared by seamer Morne Morkel for 176 off 285 balls.

The 26-year-old Kiwi ace attempted to pull a Morkel short ball but got his angles all wrong, hitting straight to Vernon Philander at deep square leg.

His innings, which took New Zealand to 6-397 by lunch time, included 16 boundaries and three sixes and was the highest score ever notched against South Africa in a Test on Kiwi soil.

It also served to equal the legendary Martin Crowe's 22-year record of 17 Test centuries for New Zealand, earned between 1982 and 1995, and to make Williamson just the sixth Kiwi to pass 5000 Test career runs.

He and Mitch Santner put on a productive 88-run fifth-wicket partnership at Seddon Park before his departure, and Santner followed suit for 41.

All-rounder de Grandhomme then spanked out a quick-fire 57 off 70 deliveries before losing his wicket and leaving Neil Wagner stranded.

On Monday, Jeet Raval also tallied a patient 88 in a 190-run stand with Williamson.

New Zealand XI: Tom Latham, Jeet Raval, Kane Williamson (c), Neil Broom, Henry Nicholls, Mitch Santner, BJ Watling (wk), Colin de Grandhomme, Matt Henry, Jeetan Patel, Neil Wagner.

South Africa XI: Theunis de Bruyn, Dean Elgar, Hashim Amla, JP Duminy, Faf du Plessis (c), Temba Bavuma, Quinton de Kock (wk), Vernon Philander, Keshav Maharaj, Morne Morkel, Kagiso Rabada.