Opting to bat in the Pool A match, Australia posted a mammoth 376 for nine against a hapless Sri Lanka side, before the islanders' innings ended at 312 in 46.2 overs.
Kumar Sangakkara tried to make a match of it, notching up his 24th ODI ton during an innings that saw him complete 14,000 runs in this format, only the second player after Sachin Tendulkar to reach the milestone.
Earlier, besides Maxwell's swashbuckling 53-ball 10, which was the second fastest World Cup hundred, the Australian scorecard was studded with three fluent half-centuries in a formidable middle-order batting performance.
Maxwell got to the three-figure mark in just 51 balls, just one short of the World Cup record held by Ireland's Kevin O'Brien.
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Skipper Michael Clarke (68), Steve Smith (72) and all-rounder Shane Watson (67) showed rampaging form during the course of their fifties as Australia sent the Lankans on a leather hunt in front of a packed house at the historic Sydney Cricket Ground.
But in the end their efforts proved to be much less than what was required, with the asking rate heading north with each delivery.
Chandimal retiring hurt at the start of the 42nd over affected the Lankans' momentum and they failed to recover from that blow, losing skipper Angelo Mathews and Thisara Perera in quick succession.
When Chandimal walked out, Sri Lanka were 280 for four with the game seemingly heading towards a close finish. But the Australians capitalised by taking a couple of quick wickets to shut the door on the opposition.