Australia boosted by Ponting ton

Ponting smashed an entertaining 101 off 126 balls before being dismissed with the last ball of the second session, but regular wickets at the other end left the hosts on 280 for six at stumps.

Vice-captain Michael Clarke (36 not out) will be entrusted with the task of trying to steer Australia to a total in the vicinity of 400 when they resume on the second morning.

Still reeling from their six-wicket loss in the opening Test, Australia did not start well - losing opener Matthew Hayden cheaply. The 37-year-old had nobody to blame but himself when he attempted to drive Makhaya Ntini but succeeded only in picking out JP Duminy at point.

Fellow opener Simon Katich appeared in outstanding form and was largely untroubled by the Proteas attack. But on 54, he played on to an innocuous delivery from Dale Steyn - who had earlier not threatened with the new ball.

Michael Hussey, who had no trouble playing the disappointing Morne Morkel, succumbed to his first delivery from Steyn when he edged behind.

However, Ponting's heroics at the other end of the crease staved off a collapse. While not the best of his career, Ponting's 37th Test century - and fourth at the MCG - was particularly sweet following a week of intense criticism in the wake of his side's first-Test defeat.

He raced through the 90s, taking just five balls to go from 87 to three figures - but his innings came to an end when he was caught at short leg by Hashim Amla off Paul Harris.

Andrew Symonds and Brad Haddin both made bright starts but could not curb their natural aggression and were both victims of outstanding slip catching.

Symonds edged Morkel to Jacques Kallis at second slip for 27, and Haddin's dismissal for 40 in the penultimate over of the day from Ntini was particularly bitter for the Australians - who had batted with tremendous application against the second new ball.