Newcomers Aaron Finch and Usman Khawaja managed just 16 and three respectively after Australia won the toss at the MCG but Hughes put on 140 with George Bailey for the third wicket at the rate of a run a ball.
Hughes reached 112 before edging Lasith Malinga to wicketkeeper Dinesh Chandimal.
Captaining the side as Michael Clarke rests the hamstring he strained in Australia's 3-0 test series win against the same opponents, Bailey struck 89 off 79 balls on a flat wicket.
Australia still looked set to fall short of 300 but David Hussey smashed 60 off 34 balls, taking 20 runs and a wide off the last over.
(Reporting by Stuart Condie; Editing by Alastair Himmer)