Mitchell Johnson has struck three times during the afternoon session of day two against South Africa to put Australia in control of the first Test match at Centurion.
The tourists resumed after lunch on 374-7, but they could only add an extra 23 runs before they were dismissed for 397.
However, the home side were soon on the back foot as Johnson took the wickets of Graeme Smith and Alviro Petersen to reduce South Africa to 15-2.
A third wicket for Johnson soon followed when he had Faf du Plessis caught by Michael Clarke for three, before Peter Siddle chipped in with the wicket of Hashim Amla for 17.
AB de Villiers fought hard at the crease to take South Africa to 63-4 at tea, but his side face a tough test to avoid facing the follow-on against a confident Australian outfit.
