HAMILTON, FEBRUARY 16

Kane Williamson made 133 in an unbroken partnership of 152 with Will Young to lead New Zealand to a seven-wicket win over South Africa on the fourth day of the second test Friday and to its first-ever series win over the Proteas.

Williamson scored centuries in both innings of the first test which New Zealand won by 281 runs.

South Africa took a 31-run first innings lead in the second test and extended that to 267 when it made 235 in its second innings.

New Zealand reached 40-1 before stumps on day three, setting up a fourth day on which it needed a further 227 while South Africa needed nine wickets to win the match and save the series.

New Zealand's total of 269-3 was its fifth-highest in a successful fourth-innings run chase.

The South Africa team is considerably under-strength as most of its leading players remained at home to play in a domestic Twenty20 league. Six Proteas players including captain Neil Brand made their debuts in the first test and the second test lineup had only 51 tests in total compared to New Zealand's 436.

The South Africa bowlers made New Zealand grind its way to a victory. The winning runs finally came in the 95th over, about 20 minutes before the end of play on day four.

Williamson's played almost a lone hand at first as he built his 32nd test century from 203 deliveries. He put on 64 for the third wicket with Rachin Ravindra who made 20 from 72 balls.

He then found a resolute partner in Young who stayed with him and was 60 not out at the close.

New Zealand was under pressure when Young came out to join Williamson at the fall of Ravindra's wicket, still needing 150 to win. Runs came slowly for him at first as Williamson approached his century but then more freely and he reached his 50 from 118 balls.

Williamson is one of only two active players along with Australia's Steve Smith to reach 32 centuries and has done so faster, in 172 innings, than Smith, Ricky Ponting, Sachin Tendulkar, Younis Khan, Sunil Gavaskar, Kumar Sangakarra, Jacques Kallis or Brian Lara, among others.

He brought to bear all of his powers of concentration in difficult batting conditions Friday with the ball turning and bouncing, occasionally spitting off a length.

Williamson is the No. 1-ranked batter in tests and showed why with three centuries in four innings in the series and a total of 403 runs at an average of 134. He batted almost 18-1/2 hours in total in the series.

"Coming into today on a wearing surface we knew we were going to have to string partnerships together," Williamson said. "Credit to South Africa. Certainly for the first couple of days they outplayed us I thought.

"We had to fight hard to get out of that position and change momentum and with the partnerships and seeing off the new ball were able to give ourselves the chance."

South Africa played much better than had been expected from a side with so little test experience, whose captain Neil Brand made his debut in the first test.

A Proteas side made up of first-class veterans and others with a smattering of test experience kept both test matches alive until late on the fourth day.

"We're definitely more disappointed after this test match, especially as we were still in it at the end of day three," Brand said. "I think the session yesterday cost us, scoring 38 for six wickets.

"We were confident coming out this morning and to be fair to our bowlers, they left nothing out there."

New Zealand won the Tangiwai Shield, a trophy being played for for the first time in a test series between New Zealand and South Africa.

The Shield, carved by an indigenous Maori master carver, commemorates the Tangiwai rail disaster of Christmas Eve 1953 when the express train between Wellington and Auckland plunged off a bridge over the Tangiwai River which had been washed away by a volcanic lahar.

New Zealand and South Africa were playing a test at Johannesburg when the disaster occurred and the New Zealand fast bowler Bob Blair was informed his fiancee had died in the disaster. An announcement was made that he would not bat in the New Zealand second innings on Boxing Day.

But at the fall of the ninth wicket, Blair appeared and added 33 runs with Bert Sutcliffe to avoid the follow-on.