South Africa 296 and 277 for 6 (Rudolph 121*, Kallis 71, Gibbs 61) trail New Zealand 595 by 22 runs

Jacques Rudolph led the South African fightback with an unbeaten 121 ... © AFP

Jacques Rudolph led the South African fightback with a spirited 121 not out, but New Zealand struck vital blows late in the day to seize the initiative. Herschelle Gibbs and Jacques Kallis chipped in with breezy half-centuries, but the loss of four quick wickets - three of them to Chris Martin - left South Africa precariously placed, still 22 runs in arrears, by the close.

The turning point came in the 72nd over of the day, 11 overs from the end. Kallis and Rudolph were sailing along, and their 146-run stand had allowed South Africa to entertain hopes of saving the match. But with the scoreboard showing 249 for 2, Craig McMillan managed some reverse-swing with his bubbly medium-pace, and beat Kallis with one that came in late. The ball kept a bit low, thudded into the pads, and Asoka de Silva upheld the appeal. Kallis thus missed out on his opportunity to equal Don Bradman's record of six hundreds in consecutive Tests.

More importantly, the momentum had shifted, and within the span of eight balls, Chris Martin had swung matters back New Zealand's way. Gary Kirsten misread a straight one, and trudged away after a forgettable 100th Test. The first ball Neil McKenzie faced was full on leg stump, and he tried to scoop it over the infield. Michael Papps leapt up and grabbed it in stunning fashion.

South Africa had lost three wickets for one run, and Martin hammered one more nail into their coffin in the penultimate over of the day: Mark Boucher poked nervously and the edge flew to first slip (272 for 6). Martin had taken four wickets in nine overs, and ten in the match, the best figures for a New Zealander against South Africa. Barring some lower-order heroics tomorrow, Martin's bowling will have decided this Test.

However, before the procession late in the day, South Africa's top order had hit back hard. Gibbs wasn't prepared to bide his time, and went after the bowlers with ferocity. By lunch, he had raced to 46, as nine fours whistled away. Two fours and a six followed after lunch, before he was rapped on the pads by one from Jacob Oram and given out. The TV replays, however, showed the ball to be missing leg stump (103 for 2).

... but Chris Martin swung it back New Zealand's way © AFP

That decision might have gone against South Africa, but there were two others that went their way. Rudolph offered no shot to Daniel Vettori when the ball appeared to be headed towards the stumps, while Kallis - on 16 - was palpably out when Scott Styris struck him on the pads with one that pitched outside off, cut back, stayed low and crashed into the front pad. The front foot wasn't too far forward and everyone, bar the umpire Aleem Dar, was convinced.

Both Jacques made the most of their reprieves. Kallis was in glorious touch right from the first ball. The first four he hit was a imperious straight-drive that burnt the grass as it zipped along. He continued in majestic vein, including a mighty six of Vettori, and brought up his fifty in 69 balls.

Rudolph wasn't as aggressive, but put away the loose stuff without any fuss. He pulled with confidence and was selective about his driving. He left most of the wide ones alone, as if making up for his first-innings dismissal, but didn't miss out on the half-volleys. Neither batsman allowed Vettori to settle, and used their feet when it was tossed up.

Rudolph reached his third Test century with a lashed pull, and continued in confident fashion while others fell around him. He wasn't troubled by the reverse-swing late in the day, and even creamed a few gorgeous fours when edges and appeals were flying at the other end. Having come in for the second ball of the innings, after Smith had been bowled by Martin, he stroked 20 fours and a six in his unbeaten effort. Yet he will have to do even more if South Africa are to stay afloat.

With the ball still new, New Zealand will smell blood tomorrow morning. They are now overwhelming favourites to go one up, with one to play. As for Martin, he just couldn't stay out of the record books. When he batted, he was bowled third ball for 0 - his ninth consecutive scoreless innings in Tests, a record.