Hashim Amla hit long-awaited form with a century in his 100th Test, while JP Duminy also passed three figures as the pair shared a mammoth partnership to punish Sri Lanka on day one at the Wanderers.
The Proteas have already wrapped up the three-Test series after wins in Port Elizabeth and Cape Town, and the scent of victory is already in the air in Johannesburg.
Having averaged 24.25 in the series before Thursday, Amla had not posted a Test century in almost a year, but the 33-year-old turned back the clock with a superb innings.
Amla also secured a slice of cricketing history, becoming just the eighth player to score a hundred in his 100th Test.
Typically patient and dominant through the covers, Amla hit an unbeaten 125, with Duminy out for 155 late in the day for a third-wicket union worth 292 runs as the Proteas reached stumps on 338-3.
After a week which has seen Kyle Abbott lead a clutch of South Africa players in ending their international careers by signing deals in England's County Championship, Amla and Duminy served as reminder of the glories that remain available with the national side.
Stephen Cook was a player that had been linked with the Kolpak exodus, but the 34-year-old remained in situ to make a first Test appearance on his home ground.
The opener's outing soon turned sour, however, as he was squared up by Sri Lanka skipper Angelo Mathews and was out lbw on 10.
Dean Elgar (27) perished in the next over, but any hopes that Sri Lanka had of getting on the front foot were swiftly and firmly extinguished by Amla and Duminy.
Amla was dropped on five when he edged Suranga Lakmal to Dhananjaya de Silva at gully and retreated into his shell somewhat after the life, allowing Duminy to take the fight to the tourists.
While Duminy had pootled along to 43 off 55 balls, Amla had contributed just six runs after 41 balls, but a flashing cut in front of square for four seemed to loosen the veteran up and he was soon on his way.
Edges that flew through the cordon helped Duminy to his fifty and his hundred, but that could not dampen the celebrations, with Amla having battened down the hatches for a 109-ball half-century - his first in 11 innings.
The aesthetic to match the scores had perhaps been lacking, but Amla quickly went about changing that, scoring another 50 runs from just 60 balls, cracking the ball to the boundary seven times in the process to bring the Wanderers to its feet.
Duminy reached another milestone in uncertain fashion - a later-than-late shot through gully taking him beyond 150, but he lasted just two more balls before edging Lahiru Kumara (2-79) to second slip to fall 11 short of his Test best score.