HAMILTON: A maiden half century by all-rounder Colin de Grandhomme helped New Zealand extend its lead over South Africa to 175 runs before its first innings ended at tea on day four of the third cricket test on Tuesday.

De Grandhomme was the last man out for 57 as New Zealand was finally dismissed for 489 in reply to South Africa's 314, having resumed this morning at 321-4.

Earlier Tuesday, New Zealand captain Kane Williamson was out for 176 after sharing partnerships of 190 with Jeet Raval (88) and of 88 with Mitchell Santner (41) which carried New Zealand past the Proteas' total

De Grandhomme's highest test score, beating his previous best of 37, and contributions from Santner and B.J. Watling (24) allowed New Zealand to build a significant lead. But the home side still had a hard job ahead of it to win the match and square the series with only four sessions remaining.

South Africa leads the series 1-0 after winning the second test in Wellington by eight wickets.

South Africa's bowlers worked hard through almost two full days to try to contain New Zealand's advantage.

Morne Morkel took on a mammoth workload as he continues his comeback from a serious back injury, bowling 36.1 overs and taking 4-100, while Kagiso Rabada bowled 34 overs and took 4-122. Left-arm spinner Keshav Maharaj bowled 50 overs and took 2-118, improving his return for the three-match series to 15 wickets.

Vernon Philander, returning from an ankle injury, went without a wicket, bowling a taxing total of 33 overs and conceding 79 runs. Philander has taken only two wickets in the series and none in the last two tests.

Williamson's innings, which was studded with milestones, was the strength of the New Zealand performance. It was his 17th test century, matching Martin Crowe's record for the most centuries by a New Zealander in tests, and at 171 his was the highest total by a New Zealand batsman in a home test against South Africa.

Early in his innings he became the sixth New Zealander to pass 5,000 test runs.

He was well assisted by Raval and de Grandhomme with their highest test scores, and by Tom Latham (50) with his 13th test half century.

Morkel's first wicket here — Latham, at 83-1 — made him the sixth South African to reach 250 test wickets.