A 200-run stand and hundreds to South Africa's two most experienced hands put the visitors in command in Dunedin, after New Zealand had begun the day strongly with bat and ball. South Africa held a 233-run lead at stumps, with seven wickets in hand and Jacques Kallis at the crease on 107.
Kallis completed his 42nd Test hundred late in the day, moving clear of Ricky Ponting to become the second most prolific century-maker of all time, after having defused early pressure from New Zealand, who had taken two wickets in an over when he came to the crease. His partnership with Graeme Smith was the first century-stand in the match, and the afternoon session the first in which no wickets fell, as New Zealand rifled through several bowling plans in their attempts to scuttle the association.
The slow scoring-rate, borne out of a tiring pitch and defensive tactics from the hosts meant South Africa could not yet make the game safe. But in a match in which neither side scored 300 in the first innings, Smith and Kallis sapped the spirit from the New Zealand attack as the day wore, and set their side on course for a massive second-innings total.
Kallis collected most of his runs square to begin with, betraying the slowness of the pitch, but added the straighter strokes from his repertoire towards the evening. Smith, meanwhile, was comfortable working the ball to his favoured leg side, but was forced to be more reticent than usual, as the hosts' seamers bowled wide outside off stump to him, with several catchers behind the stumps awaiting a loose stroke. Both men were happy to wait for the poor deliveries, and in contrast to Ross Taylor and Brendon McCullum on the previous day, were satisfied to accumulate steadily, instead of searching for bursts of quick runs.
Doug Bracewell took all three wickets, and was the most threatening bowler throughout the day. He extracted movement through the air and off the pitch in his first spell, nailing Hashim Amla for nought with a super outswinger, albeit one that pitched well wide of off stump. His spell with the second new ball was no less impressive towards the close of play, creating two strong lbw appeals as well as bowling Smith with one that nipped off the seam to take a deflection off the inside edge.
In between the two new-ball spells though, New Zealand looked alarmingly toothless. Chris Martin, the prime destroyer in South Africa's first innings, could barely beat an edge in his 17 overs that were notable for their lack of movement. Tim Southee tried several plans of attack, to various fields, first trying to take the ball away from Kallis with a stacked slip cordon, before coming back with an aging ball to rattle him with reverse-swing. Neither ploy flustered the batsmen, who were glad for straight, full deliveries from Southee, having had plenty to watch through to the keeper from others who bowled wide.
Daniel Vettori looked New Zealand's best chance of prising a scalp through the third-wicket stand, but despite turn, flight and three close catchers to Smith, he could force neither an edge nor a false shot. One hopeful shout for lbw was shown to be missing off stump, and though he proved more difficult to score off than the seamers - he did not pose a trial either.
New Zealand created chances in the overs following tea, but twice Martin Guptill was too deep to snaffle thick edges - one each from Kallis and Smith - and two more times run-out opportunities requiring direct hits were missed. New Zealand stuck to the wide line outside off stump to Smith, hoping to draw a rash stroke, and he almost succumbed in the 90s, when the scoring rate roused his frustration. Occasionally he flashed and missed, reminding himself to rein in the cover drive. But as a tight offside in-field constricted him further, he couldn't help but reach, even moving across the stumps to toe-end a ball from Tim Southee that barely landed on the strip.
He batted out six tense dot balls from Vettori on 99, but Smith eventually reached triple-figures - a good omen for the visitors who have never lost on the previous 23 occasions Smith made hundred. But just as his scoring trended north, Kallis slowed dramatically at the other end, having parked himself on 90. After 24 dot balls there, he began to move again, taking five more overs to reach triple-figures.
Jacques Rudolph was sent in ahead of AB de Villiers and survived an lbw appeal off Bracewell that was overturned in his favour upon review. South Africa will press for a definitive advantage tomorrow, with plenty of batting still to come.