Hashim Amla remained unbeaten on 99, as he would look forward to register his 18th Test century on Sunday. Amla's 84-ball knock included 10 boundaries.
While Australians struggled to score runs in the first innings, as they were restricted to 163, South Africa's Hashim Amla and Graeme Smith tore apart the Aussie pace-attack as they scored at 6 runs per over in the second innings to end the day with lead of over 250.
Hashim Amla (99*), Smith (84) added 178 runs for the second wicket, and made batting look very easy as Aussies had struggled to score runs during the first two sessions of the day.
Jacques Kallis (17*) and Hashim Amla added 24 runs for the third wicket and would resume batting on Day 3, and look to get to a target close to 400-450.
Having scored 230/2 on Day 2, visitors have registered a lead of 292 runs. Given Australia's first innings performance, Proteas hold the edge as they have runs and bowlers to torment the hosts when they resume play on Day 3.
Tea Report: South Africa started off well as they scored 24 runs without losing any wickets, to lead by 86 runs after restricting Australia to 163 in their first innings on Day 2 of the Perth Test on Saturday.
Resuming play after Lunch, South African bowlers tapered Australia's tail-enders as they added 45 runs after Lunch, and lost the remaining 3 wickets.
Peterson picked all the three wickets after lunch, as Aussies were bundled out for 163, trail by 62 runs.
Matthew Wade top scored for Australia with 68, while John Hastings scored 32 runs adding 40 runs for the eighth wicket.
Lunch Report: South Africa's Dale Steyn removes Australian top order as the hosts were reduced to 118/7 at the end of the first session on Day 2 at Perth.
Starting the day with 33/2, Australia were tormented by South African bowlers, as they threatened more than the hosts picking 5 wickets for 85 runs, as Australians trail by 107.
The only highlight of the session for Australia was Matthew Wade's valiant 60 (not out) as he added 55 runs with Michael Hussey until the latter was dismissed Morkel for 12.
Ricky Ponting playing his last Test, having announced his retirement from international cricket, failed to perform well as he was dismissed by Philander for 4.
Clarke also followed his former skipper within a gap of six balls as he was dismissed by Steyn for 5 in the 17th over of the innings.
Steyn has been magnificent, with figures of 4/33, threatening to aim for more, as the post lunch session happens to be very important for Australians as they depend wholly on Wade, who is at the crease, having scored an unbeaten 60.
In reply to South Africa's 225, Australia lost Cowan (0), Watson (10), David Warner (13), Nathan Lyon (7), Ricky Ponting (4), Michael Clarke (5) early in the innings, as Aussies were struggling at 45/6 after 17 overs.