Graeme Smith hit an unbeaten knock of 57 as South Africa fought back on day two of the second Test match at Adelaide.

Australia had earlier been dismissed for 550 after a double hundred from Michael Clarke on an unresponsive pitch.

However, after toiling in the field, it was South Africa's turn to reap the benefits of little assistance for the seam bowlers as Smith and Alviro Petersen struck back.

Smith reached his 50 off 98 balls while Petersen complemented his captain's innings with a supportive 47 to leave their side 368 runs behind.