Summary Ponting (4) faced seven balls before he was trapped lbw by Vernon Philander.
PERTH, Australia: South Africa s pacemen ripped through Australia s top order with Dale Steyn snaring four wickets as the hosts struggled to 118-7 at lunch on Saturday in reply to 225 on the second morning of the third test.
Australia was reeling at 45-6 after losing 4-11 in 4.1 overs, including ex-skipper Ricky Ponting (4) and captain Michael Clarke (5), before Matthew Wade combined with Mike Hussey in a seventh-wicket stand to lift the hosts to 100.
Wade was unbeaten on 60 at the interval, his counterpunching innings containing five fours and three sixes. He hit allrounder Robin Peterson for six to raise his half century from 51 balls.
Steyn, the top-rated bowler in test cricket, belatedly made a mark on the series with figures on the second morning of 3-12 in six overs, including a pair in his first over.
The fast and bouncy WACA pitch is destined to produce a result and likely determine the No. 1 test ranking, with 17 wickets already falling in the first four sessions. South Africa needs only a draw to retain top spot, with Australia requiring a victory.
Australia resumed the second day at 33-2 and only added two runs before opener David Warner (13) was caught behind, playing rashly outside off stump to Steyn to trigger a half hour of carnage.
Ponting got a standing ovation from the crowd when he went in to bat in his 168th and last test match and got off the mark quickly with a single, then watched as night watchman Nathan Lyon was out two balls later, slicing Steyn to Faf du Plessis at gully.
Ponting (4) faced seven balls before he was trapped lbw by Vernon Philander, and his referral to the third umpire was rejected when replays showed the ball hitting him in front on the knee roll.
Australia s position deteriorated further when Clarke (5) got an edge to a perfect away swinger from Steyn to make the total 45-6. It was Clarke s first serious failure of the series, after scoring double centuries in the first innings of both the drawn first and second tests.
Yet it could have been worse for Australia. Wade should have been out without scoring but Hashim Amla missed a run-out chance at the striker s end after Hussey took off for a dangerous, quick single.
The seventh-wicket pair settled in and set about reducing the deficit. Wade hooked Philander for six and struck a four in the same over, which cost 11 runs. He also drove Robin Peterson over long-on for six in a 55-run partnership to lift Australia to 100 before Hussey (12) edged Morne Morkel to Graeme Smith at slip.
John Hastings, playing his first test, survived the 22 minutes until the end of the first session.
