Australia have headed into lunch on the second day of their third Test match trailing South Africa by 107 runs with just three wickets remaining.
The hosts ended the morning session in Perth on 118-7 in response to South Africa's first innings total of 225, having resumed the day on 33-2.
Wicketkeeper Matthew Wade is currently unbeaten on 60 runs, while John Hastings is two not out.
Dale Steyn has proved to be the visitors' most impressive bowler so far in the match, having picked up four wickets for 33 runs.