World champions New Zealand's slump continues with third defeat in six Tests

World Test champions New Zealand suffered another disconcerting defeat at home, losing to South Africa by a massive 198 runs in the second Test in Christchurch on Tuesday.

The loss was New Zealand's third in their last six Tests following their win in the World Test Championships final. Since then, the Black Caps lost to India in Mumbai by 372 runs, were stunned by Bangladesh in Mount Maunganui by eight wickets and were again crushed by the Proteas on Tuesday.

They only managed to avoid defeat in the opening Test in India in November by holding on for a draw with one wicket hand.

New Zealand went into the final day at 94-4 and were out just after tea for 227 chasing a target of 426.

South Africa's pace spearhead Kagiso Rabada was named player of the match after taking eight wickets and blasting 47 runs in the second innings as the tourists piled on 354-9 declared to set up the win.

It leaves New Zealand sixth in the nine-team standings with 28 points from six Tests while South Africa are fourth with 36 from five matches.

"I'm so disappointed to be in this position," New Zealand's stand-in captain and opener Tom Latham said.

"Obviously you go out with the ambition of winning every Test match you play, especially at home. When we head to England in a few months it's important we shift our focus and try our best to win that series over there and get as many points as we can."

With the teams ranked by the win percentage, Sri Lanka head the championship table with two from two (100 per cent), followed by Australia (86.66%) with four wins from five followed by Pakistan with three from four for 75%.

Sri Lanka start a two-Test series in India this week while Australia have a three-Test series against Pakistan starting in Rawalpindi on Friday.

South Africa captain Dean Elgar felt vindicated after his "bold" decision to bat first paved the way for a dominant second Test win.

Despite a green-tinged wicket and New Zealand's unbeaten record at Hagley Oval when fielding first, Elgar backed his batsmen to turn things around after an innings defeat in the first Test.

The Proteas made 364 in the first innings and pressed the advantage in the second.

"Bold decision and one we had to take as a unit, luckily it paid off for us," said Elgar..

"It might have backfired on us and I would've looked like an absolute idiot. I am one of those guys who live for the decisions that I make for the side."

South Africa leave New Zealand with their proud record of never losing a Test series to the Black Caps intact, a run that dates back to 1931/32.