LIVE SCORING
Earlier, Shane Watson took 5-17 in a devastating five-over spell after lunch as Australia ripped South Africa out for 96 for a 188-run first-innings lead.
Watson dismissed Hashim Amla and Jacques Kallis in the first over of the afternoon session to start the slide, South losing 9-47 after the lunch break.
Watson bowled captain Graeme Smith for 37 four overs later and had Ashwell Prince lbw next ball as South Africa disintegrated from 49-1.
Ryan Harris grabbed 4-33 to help Australia turn the Test on its head after starting the second day under pressure at 214-8.
Captain Michael Clarke made 151 to lift Australia to 284 before their bowlers put the tourists in complete control.
Shane Watson took 5-17 in a devastating five-over spell after lunch as Australia ripped South Africa out for 96 for a 188-run first-innings lead on the second day of the opening Test on Thursday.Scores:
Australia 284 (M. Clarke 151; D. Steyn 4-55) and 13-3 v South Africa 96 (S. Watson 5-17, R. Harris 4-33)