Proteas take control in Dunedin
Graeme Smith and Jacques Kallis hit centuries to give South Africa the upper hand after day three of the first Test in New Zealand.
The experienced duo shared a 200-run partnership for the third wicket before captain Smith fell for 115. Kallis ended the day unbeaten on 107 as the Proteas reached 268-3 - a lead of 233.
The Black Caps had resumed on Friday with a lead of five runs after reaching 243-9 at stumps, but Trent Boult's spirited 33 off 28 balls took the hosts' score to 273.
Chris Martin's was the wicket to fall, the last man dismissed for five to become Dale Steyn's second victim of the innings at University Oval.
That left the impressive Boult unbeaten following his profitable stint at the crease, which was highlighted by three sixes in one over against a beleaguered Vernon Philander.
The tourists' second innings got off to a rocky start as Doug Bracewell roared in to dismiss Alviro Petersen and Hashim Amla in the 12th over.
Petersen was smartly snapped up by Tim Southee at mid-off for 25 and then, four balls later, Amla (two) was sent on his way by a brilliant one-handed catch at second slip by Martin Guptill.
That brought Kallis out to join Smith at 47-2, though, and saw an end to New Zealand's promising start with the ball.
The former survived a couple of scares, Bracewell and Boult troubling the classy all-rounder early on, but when he and Smith got in they looked assured.
Smith edged just short of Guptill at wide slip in the 90s before reaching three figures - his 24th at Test level - but then chopped on to Bracewell with the second new ball.
Kallis had a let-off on 78 when he was well short after being sent back, Rob Nicol missing the run-out chance from cover.
The 36-year-old duly went on to become the sole owner of second place on the all-time century-makers list with his 42nd hundred - his sixth ton against New Zealand.
Bracewell finished the day with 3-53 and would have had a fourth wicket had Jacques Rudolph (13no) not reviewed a leg before decision that was shown to be pitching just outside leg stump.
Earlier in the day, New Zealand wicketkeeper McCullum was taken to hospital for precautionary scans after sustaining bruising when diving in the outfield.