Australia captain Aaron Finch and pace bowler Mitchell Starc stole the show as the World Cup holders eased to an 87-run win over Sri Lanka at the Oval on Saturday.
Finch equalled his career-best one-day international score with a masterful 153 and Steve Smith chipped in with 73 as Australia scored an imposing 334-7.
Needing a World Cup record run-chase to claim a shock win, Sri Lanka got off to a flying start thanks to a first-wicket partnership of 115 between captain Dimuth Karunaratne and Kusal Perera.
But Perera departed for 52 and when Karunaratne fell on 97 the game swung back in Australia's direction.
Starc was the catalyst, with a fiery spell of three wickets in six balls, Australia eventually dismissing Sri Lanka for 247 thanks in large part to his 4-55 from 10 overs.
Australia: Aaron Finch(c), David Warner, Steven Smith, Usman Khawaja, Shaun Marsh, Glenn Maxwell, Alex Carey(w), Pat Cummins, Mitchell Starc, Kane Richardson, Jason Behrendorff
Sri Lanka: Dimuth Karunaratne(c), Kusal Perera(w), Lahiru Thirimanne, Kusal Mendis, Angelo Mathews, Dhananjaya de Silva, Thisara Perera, Isuru Udana, Milinda Siriwardana, Lasith Malinga, Nuwan Pradeep
(With inputs from AFP)