South Africa beat Australia by 40 runs in Hobart to win their one-day series 2-1 and inflict another defeat on Justin Langer's misfiring side.

Set 321 to win after David Miller and Faf du Plessis hit centuries, Australia could only manage 280-9 off their 50 overs despite a battling 106 from Shaun Marsh.

The Proteas won the opening game of the series by six wickets and Australia snapped their seven-game losing streak to clinch the second by seven runs.