Michael Hussey top-scored with unbeaten 64 while Michael Clarke made 50. The duo revived tottering Aussie innings with a 90-run stand for the fifth wicket.
Australia, sent in to bat under overcast skies, slumped to 54/4 after yet another below-par performance from its top-order before Hussey and Clarke staged a fine recovery act.
It is the second time in as many matches at the MCG that Australia has failed to pass 200.
However, the home side, despite the absence of pace spearhead Brett Lee, will still back itself to defend the modest total, particularly against Lankan under-performing line-up.
Hussey and Clarke were rewarded for playing themselves in on a wicket which did not allow batsmen to hit confidently thro' the line.
There were just eight boundaries in the entire innings.
With boundaries hard to come by, both players were forced to take on Lankan fielders, both in and outside the circle, to scrounge their runs.
Their 90-run stand came off 126 deliveries and was the only time the Australian batsmen were not threatened by the Sri Lankan attack.
For a change it was Maharoof, who inflicted the damage on Aussie line-up, rather then the regulars-Murali and Vaas.
The right-arm quick, who bowled his 10 overs in a single go, snared the wickets of Matthew Hayden and Andrew Symonds and also played a key role in the run out of skipper Ricky Ponting, who made just 11 to continue his lean patch.
It could have been worse for Ponting, who was grassed before he had scored by Tillakaratne Dilshan at point.
Australia was on the back foot after Adam Gilchrist, Ponting, Hayden and Symonds all departed cheaply before the completion of the 22nd over.
Clarke and Hussey steadied the innings but the former's departure to a two-grab catch from Muralidaran in the 43rd over prevented Australia from accelerating its run rate in the final overs.
It managed just a relatively modest 50 runs in the final 10 overs, during which it failed to find the boundary.
Australia 187/7 in 50 overs (Hussey 64 n o, Clarke 50, Hayden 23; Maharoof 2 for 20, Murali 2 for 37, Vaas 1 for 34) Vs Lanka