PERTH, AUSTRALIA - NOVEMBER 30: Mitchell Starc of Australia celebrates the wicket of Alviro Peterson of South Africa during day one of the Third Test Match between Australia and South Africa at WACA on November 30, 2012 in Perth, Australia. (Photo by Paul Kane/Getty Images)

Perth – Australian paceman Mitchell Starc rocked South Africa with two wickets in six balls just before lunch to help reduce the tourists to 63/3 after the opening session of the third and final Test on Friday.

The South Africans, needing at least a draw to retain their top Test ranking, endured a searching examination from an overhauled Australian pace attack but looked set to reach lunch for the loss of only Graeme Smith when Starc intervened.

The leftarmer, 12th man in the drawn Tests in Brisbane and Adelaide, removed opener Alviro Petersen (30) and all rounder Jacques Kallis (2) with similar balls that swung late and ripped through the gate to smash the wickets.

Another recalled leftarmer, Mitchell Johnson, got the most movement out of a Waca track early on a bright sunny morning but it was all rounder Shane Watson, returning from a calf injury, who claimed the wicket of skipper Smith for 16.

Australia gave a debut to John Hastings after dropping exhausted pacemen Ben Hilfenhaus and Peter Siddle and he opened the bowling with Starc.

Starc looked to have made the breakthrough when the tourists had made just 11 runs but umpire Richard Kettleborough was forced to overturn his lbw decision when TV replays showed the ball would have missed Petersen's leg stump.

The tourists had made another 27 runs when Watson angled a delivery across lefthander Smith and the ball took a healthy edge before Michael Clarke snaffled it up in the slips.

As well as the series, the number one ranking in Test cricket is on the line in the match with the hosts needing a win to return to the summit of the game.

South Africa, who won the toss and elected to bat, gave a debut to batsman and occasional spinner Dean Elgar and replaced hapless specialist spinner Imran Tahir with Robin Peterson. – Reuters