Seamers Sean Abbott and Nathan Ellis took three wickets each as Australia restricted South Africa to 164 for eight in the second Twenty20 international at Kingsmead on Friday.
Abbott claimed three for 22 and Ellis took three for 25 after Australia decided to bowl on a pitch which Ellis said had "a little bit more in it than the other night" on a cool, overcast evening after rain shortly before the start.
Australia won the first match by 111 runs at the same venue on Wednesday.
Temba Bavuma gave South Africa a fast start, scoring 35 off 17 balls, before he was Abbott’s first victim. South Africa lost four wickets for ten runs in 17 balls, including a double-wicket maiden by Ellis, as they slumped to 46 for four.
Captain Aiden Markram hit 49 and put on 51 for the fifth wicket with Tristan Stubbs (27) in a partial recovery by the hosts.
Brief scores:
South Africa 164-8 in 20 overs (T. Bavuma 35, A. Markram 49; J. Behrendorff 2-25, S Abbott 3-22, N. Ellis 3-25).