Showing no signs of being undercooked after not appearing against the Lions in the six warm-up games of the tour, the Springboks destroyed the much-feted Lions set-piece in the first-half, outpowering the scrum and pinching line-out ball. They also used the rolling maul to great effect and dominated the loose.
Outstanding Zimbabwe-born Bok loosehead Tendai Mtawarira, to cries of "Beast" from the crowd, fairly crushed Phil Vickery, who gave away a hatful of kickable penalties and was replaced after 45 minutes.
The home side scored tries through captain John Smit and flanker Heinrich Brussow, with Ruan Pienaar bagging 13 points with the boot and Frans Steyn one long-range penalty.
The Lions responded with tries from Tom Croft (2) and Mike Phillips, all converted by Stephen Jones.
The match started in dramatic fashion.
After stealing a Lions line-out, the cool Pienaar caught Ugo Monye napping with a chip to the corner, JP Pietersen forcing the English winger and ball over the line for a home five-metre scrum.
The Boks ran through three phases with Smit eventually barreling his way over from short range through the tackles of Jamie Roberts and Croft for a try that Pienaar converted.
But the Lions roared straight back, capitalising on a spilled ball by Steyn from the restart. After a couple of reset scrums, the ball was whipped wide and a mispass saw Monye in at the corner, only for referee Bryce Lawrence to disallow the try after consulting the television official.
Vickery was then penalised for popping up out of the scrum and Pienaar hit the first three-pointer of the game to stretch the Boks out to a 10-0 lead.
The Lions looked threatening whenever they had ball in hand, however, and a delightful pop-pass from Lee Mears saw David Wallace burst clear but with no support at hand.
On a windless afternoon, Jones missed a second penalty after Bryan Habana held on under pressure from Gethin Jenkins at the ensuing clearance.
A late tackle from Croft on Fourie du Preez as the scrumhalf accelerated down the touchline saw an immediate penalty that Steyn knocked over from long-distance.
But again the Lions came back, Croft making amends by rounding off a move started by Roberts putting Brian O’Driscoll into space in midfield.
Pienaar added his second penalty after a Steyn miss, again after Vickery was flagged for collapsing a scrum in front of the posts under pressure from Mtawarira.
When Tommy Bowe was caught in possession a minute later, Pienaar was again unerring with his boot from close to touch, but then failed to capitalise on another Vickery penalty, to make the half-time score 19-7.
A 30-metre rolling Bok maul seemed likely to set the scene for the second period, with Vickery replaced by Adam Jones after five minutes.
Pienaar shunned a kick at goal for the corner, setting up a catch-and-drive from the line-out, Brussow crossing under a mass of bodies for a try Pienaar converted.
With two more Tests to come at altitude in Pretoria and Johannesburg, this game in the Indian Ocean seaport city was seen as perhaps the Lions’ best chance at an early scalp.
And the Lions, with Roberts increasingly to the fore, made sure of a thrilling climax with two late converted tries.
With 12 minutes remaining, Croft crossed for his second, again after an O’Driscoll pass played him into space close to the line.
Replacement Morne Steyn then produced a try-saving tackle on Monye, dislodging the ball as the winger was about to dot down.
But the pressure paid off for the Lions with Phillips crossing for a third try converted by Jones.
When Jones kicked to the corner with two minutes to play, the Boks pinched the line-out and cleared their lines for a vital win.