A cultured Hashim Amla and controlled AB de Villiers established a priceless partnership to take South Africa's advantage to a considerable 199 over Australia on day three.
Each were close to being dismissed by Pat Cummins in the first over after lunch, but they survived the bullets of the 18-year-old debutant and defused the other significant threat of the spinner Nathan Lyon on a wearing pitch. Ultimately, when bad light ended play early again, they would walk off happily, having taken command at a Wanderers ground populated by the most bountiful crowd of the Test.
Australia's captain Michael Clarke sorely missed the bowling of his deputy Shane Watson, rendered immobile by a hamstring complaint, and leaned heavily on Cummins, who already looks a level above the other members of the touring attack. His morning spell to Jacques Kallis was compelling, and provided cause for Australian optimism even as Amla and de Villiers showed immense poise to build a union from the uncertain beginning of 90 for 3.
What Cummins lacked most of all was support, for Mitchell Johnson and Peter Siddle in particular were unable to generate the sort of chances that their seniority and past experience in South Africa should have demanded. As with Ricky Ponting and Brad Haddin, their international careers may soon be marked harshly on this evidence.
Already 59 overs have been lost to the weather, and South Africa may be little more than another session's batting from pushing their lead beyond Australia's reach - even if the tourists manage to rid themselves of the batting horrors of Cape Town and the first innings in Johnannesburg.
Sunnier skies at the start of the day had Johnson resuming the attack, completing his opening over with a shortened run-up. The gambit seemed to be geared towards achieving a higher-arm action and a greater chance of swing, but it brought no early wickets as Australia's narrow lead was quickly swallowed up.
Cummins was much the more vexing proposition for the openers, and after Jacques Rudolph had made a fluent start he hooked unwisely at a swift short ball and skied the simplest of chances for Haddin. Graeme Smith interspersed edges through the third-man region with the occasional sparkling drive and was looking good for more when spin was introduced.
Lyon dropped onto a nice length in his first over to Amla, and then set about tempting Smith outside off stump. A modicum of rough provided the natural variation that Lyon enjoys, and when one ball bounced and turned a little more than Smith budgeted for, the airborne cut was taken in the gully.
Clarke immediately took Lyon off to try Cummins, who set about Kallis with all the venom of a genuine strike bowler. In the space of 19 balls - reminiscent of Ishant Sharma's fabled spell to Ponting in Perth in 2008 - Cummins made Kallis look decidedly uncomfortable, no more so than when one throat ball was only parried down off glove and bat handle with a fair helping of luck. An airy play and miss soon followed, and the bowler completed a comprehensive victory over his quarry when Kallis sparred at a delivery seaming away and edged to Clarke at slip.
Not content with Kallis' wicket, Cummins soon had de Villiers hopping around and calling for medical attention when a searing yorker struck him on the boot, and South Africa's batsmen were happy to see lunch.
On resumption Cummins went desperately close to removing both batsmen in the first over of the afternoon. After de Villiers presented a difficult return catch that failed to go to hand, Amla was pinned in front of his stumps, but was given not out by the umpire Billy Bowden. Australia's referral was well-founded, but millimetres shy of matching the ICC's parameters to overturn the original call.
Two overs were all Clarke asked of Cummins, before he embarked upon something of a holding operation in which he rotated his bowlers briskly in the absence of Watson and even delivered two overs himself. Amla and de Villiers attacked when they could but also throttled back at times, careful not to over-reach as South Africa had done on day one.
Lyon was partially blunted via the use of sweeps and reverse sweeps, Peter Siddle bowled presentably, and Johnson achieved some of his desired swing from a reduced run-up. But the tourists' hopes were now heavily pinned on Cummins, who in his second spell of the session lacked some of the rhythm and energy of the morning, spearing a few too many projectiles down the legside.
Tea came and went but the skies were darkening as Amla and de Villiers resumed. They added another 38 runs against opposition that had started to look beleaguered, de Villiers advancing to swing Lyon into the stands at wide long-on and Amla showing heavenly balance to twice dispatch Johnson through the covers.
As speculation swirled ever more intensely around Ponting's future, he was brought on to bowl in dying light - to a chorus of boos, no less - and swung the ball a little. It would be the final over of a day that shaped initially towards the fielding side, but for the first time in the match ended with the batsmen very much in command.