Perth: Australia lost four quick wickets in Friday's morning session but a quick-fire 97 by David Warner meant the hosts still had the upper hand at lunch on day two of the first test against South Africa at the WACA Ground.
In reply to South Africa 242 all out on the first day, Australia went to lunch on 181-4, with Adam Voges unbeaten on 10.
Australia lost opener Shaun Marsh (63) to the last ball before lunch, trapped lbw by swing bowler Vernon Philander (1-49). Marsh batted for just over three hours, hit seven fours and featured in a 158-run opening stand.
Warner was racing toward his 17th career century when he pushed at a Dale Steyn delivery away from the body, and was caught by first slip Hashim Amla.
Warner's dismissal triggered a top-order collapse as Australia lost Usman Khawaja (4), skipper Steve Smith (0), and Marsh in the space of 23 runs.
Khawaja was yorked by Kagiso Rabada, and two overs later, debutant Keshav Mahraj dismissed Smith lbw for his maiden test scalp.
Soon after dismissing Warner, Steyn left the field after aggravating an old shoulder injury and was taken to a nearby hospital for scans and treatment.
Maharaj completed Steyn's unfinished over and in his very next over trapped Smith, who unsuccessfully reviewed the on-field decision.
Resuming the day on 105 without loss, Warner and Marsh were largely untroubled prior to the late top-order collapse, as the tourists bowled either too full or short.
Warner batted for 2 1/2 hours and hit a six and 16 fours. He has shared century opening stands in each of the past three tests against South Africa, after he and Chris Rogers put on 126 and 123 in the last two tests of the 2013/14 series.