Mark Boucher and AB de Villiers put South Africa in complete command as the home team reached 324 for five at lunch on the third day of the fourth and final Test against England on Saturday.
Boucher hit 51 not out and De Villiers was unbeaten on 43, the pair sharing an unbroken partnership of 89 to help South Africa establish a 144-run lead.
The hosts started the day on 215 for two with Hashim Amla on 73 and Jacques Kallis on seven.
Kallis was caught off Ryan Sidebottom for his overnight score and Amla fell to Stuart Broad for 75 as England picked up two quick wickets.
JP Duminy, under pressure for his place after a run of low scores, was then dismissed for seven by off-spinner Graeme Swann.
However, Boucher and De Villiers put South Africa back on top although the latter twice referred successful appeals by Swann to the third umpire, Daryl Harper overturning both decisions.
Boucher also survived a referral by the same bowler.
England are 1-0 up in the series. – Reuters