Alviro's century saves the A team

Alviro Petersen muscled his way back into the national selectors' minds with a century on the second day of the match between South Africa A and Australia in Potchefstroom.

His hundred brought calm to an otherwise frenetic day, in which 13 wickets fell, five of them to Titans speedster Marchant de Lange.

Australia resumed with Shaun Marsh and Michael Clarke fairly settled.

Vernon Philander rattled Marsh on the helmet with a bouncer just after the Aussie had reached a half-century.

A few runs later, Marsh was caught at mid-on, miscuing a hook off De Lange.

This started a collapse in which six wickets fell for 26.

A last-wicket partnership of 58 between Michael Hussey and Nathan Lyon troubled South Africa A until Robin Peterson trapped Lyon lbw with his second ball of the day. Australia's 53-run lead looked greater when Dean Elgar and Stiaan van Zyl both fell without a run on the board.

Mitchell Johnson could also have had Petersen's wicket but Ricky Ponting dropped an edge at third slip.

Petersen made the most of that lifeline and dispatched Peter Siddle's first over for four boundaries, pulling and cutting with extravagance.

Together with JP Duminy, who scored a careful 32, he wiped off the deficit and put South Africa A in safer territory.

When Lyon removed Duminy and Farhaan Behardien in consecutive deliveries, Petersen stayed calm.

He and Thami Tsolekile played more freely as the pitch flattened in the afternoon and Petersen reached his century before being dismissed by Trent Copeland minutes before the close of play.

Tsolekile followed off the bowling of Peter Siddle, becoming the sixth lbw victim of the day. With four wickets left in their second innings, South Africa A lead by 151 runs.