An unbeaten 93 from David Warner has helped Australia extend their advantage over South Africa to 338 runs
The opener wasn't at his best during the afternoon session, but after being dropped on three occasions, he made the hosts pay by taking Australia to 147-1.
After resuming after lunch on 18-1, Warner and Alex Doolan pressed on to add to their 209-run lead as South Africa tried to find a way back into the match.
With Warner going along at a brisk pace at one end, he was supported by debutant Doolan, who remained composed on his first appearance in the Test arena.
After taking Australia to three figures with 20 minutes of the session remaining, Warner went on the attack to reach tea with 11 boundaries and two sixes, while Doolan neared his half-century with 48 off 85 balls.