ADELAIDE — Graeme Smith struck a defiant century in the face of Australia's massive first innings total of 550, but the host grabbed a pair of wickets after tea to restrict South Africa to 217 for two at the close of the second day of the second Test. With Australia's bowlers toiling fruitlessly on a flat wicket during the heat of the day, the South Africa captain nudged his team steadily forward, but opener Alviro Petersen and Hashim Amla suffered brain-fades to lose their wickets. Having raised his 26th Test century, the barrel-chested skipper was unbeaten on 111, with Jacques Rudolph on 25. Resuming on 117-0, Petersen added 21 runs with Smith after tea but their partnership was broken by a poorly judged attempt at a single and a sprightly 37-year-old in Mike Hussey. After driving spinner Nathan Lyon to mid-on, Petersen swerved to avoid Smith down the pitch and was a few centimeters short of safety when Hussey swooped and threw down the stumps with a direct hit. Having been frustrated by the pair for more than a session, the Australians celebrated wildly as Petersen trudged off, having eased off in his dash to the crease, thinking he was safely home. Australia was convinced it had its second wicket four overs later when Smith was given out caught behind when on 78, but the decision was over-ruled after video review, leaving paceman James Pattinson biting his lip in frustration. The reprieve was Smith's second in his innings after he survived a stumping chance on 46 when wicketkeeper Matthew Wade fumbled a Lyon delivery behind the stumps with the Proteas skipper well out of his crease. Wade later made amends when Amla charged out of his crease against part-time leg-spinner David Warner, only to be beaten for flight and have the bails whipped off. Smith marched resolutely forward and sliced Lyon to the fence to complete a morale-boosting and no-nonsense knock of 12 boundaries, in contrast to the fireworks of Australia captain Michael Clarke and David Warner on day one. Amla's dismissal for 11 brought in Rudolph, taking Jacques Kallis' fourth spot in the order to relieve the burly all-rounder, who suffered a hamstring strain when bowling on the opening day. Rudolph survived the last over from Lyon, and he and Smith strode off with South Africa still trailing by 333 runs. The tourists earlier rattled through the last five wickets for 68 runs to dismiss the host shortly before lunch. — Agencies Scoreboard Australia (1st Innings) Warner c Smith b Morkel 119 Cowan c and b Kallis 10 Quiney c Smith b Morkel 00 Ponting b Kallis 04 Clarke b Morkel 230 M. Hussey b Steyn 103 Wade c De Villiers b Morkel 06 Siddle c Smith b Kleinveldt 06 Pattinson c Smith b Steyn 42 Hilfenhaus c Kleinveldt b Morkel 00 Lyon not out 07 Extras (lb11, w1, nb11) 23 Total (all out, 107.2 overs) 550 Falls: 1-43 (Cowan), 2-44 (Quiney), 3-55 (Ponting), 4-210 (Warner), 5-482 (Hussey), 6-494 (Clarke), 7-501 (Wade), 8-503 (Hilfenhaus), 9-504 (Hilfenhaus), 10-550 (Pattinson). Bowling: Steyn 23.4-4-79-2, Morkel 30-5-146-5, Kallis 3.3-1-19-2, Kleinveldt 20.1-4-81-1 (6nb, 1w), Tahir 23-0-180-0 (5nb), Du Plessis 7-0-34-0. South Africa (1st Innings) Smith not out 111 Petersen run out (Hussey) 54 Amla stumped Wade b Warner 11 Rudolph not out 25 Extras (b7, lb2, w3, nb4) 16 Total (2 wkts, 67 overs) 217 Falls: 1-138 (Petersen), 2-169 (Amla). Bowling: Hilfenhaus 12-4-36-0, Pattinson 8-0-40-0 (4nb, 1w), Lyon 24-2-53-0, Siddle 12-3-34-0, Clarke 3-0-10-0, Hussey 1-0-7-0 (2w), Warner 5-0-27-1, Quiney 2-1-1-0.