Australia made 5-305 off its 50 overs to start the match with man-of-the-match Phil Hughes starring with 112 as he became Australia's first one-day international debutant to score a century.
Sri Lanka was 2-17 early on before Tillakaratne Dilshan and Chandimal did well to give them a sniff, but the tourists lost 3-17 with three consecutive run outs ending their hopes of a morale-boosting victory after losing the Test series 3-0.
Sri Lanka made a horror start to the run chase losing Upul Tharanga for one and Mahela Jayawardene for five, but Dilshan and Chandimal did well resurrecting the tourists' innings.
The pair combined for a solid partnership of 94 before the run out disasters began. That ended Sri Lanka's hopes of chasing down Australia's big total and coincided with Chandimal suffering from a hamstring injury.
Dilshan returned to some of the form he showed with 143 in the First Test against Australia in Hobart making 51 from 70 deliveries with four boundaries before being the first run out victim for Sri Lanka.
Angelo Mathews joined Chandimal at the wicket after Dilshan was out, and he looked good with 12 off 14 balls in quick time before Glenn Maxwell ran him out. Lahiru Thirimanne then made it three run outs on the trot when he was found short again by Maxwell without even facing a ball.
Jeevan Mendis played a nice little cameo with 20 off 18 balls with a four and a six before being caught by George Bailey off Mitchell Johnson to leave Sri Lanka 6-167.
Wicket-keeper batsman Chandimal did well with both the gloves and bat in the Third Test in Sydney, and took that confidence into the 50-over but when he was out for 73 from 95 balls Sri Lanka was never going to last much longer.
The score was then 7-169 and Sri Lanka was quickly bowled out for 198 from 40 overs with Nuwan Kulasekara offering some fight with 18 off 15 balls before he was also caught by Bailey off Clint McKay.
McKay was the star with the ball for Australia finishing with 4-33 from eight overs. Johnson picked up 2-43 as well and Mitchell Starc 1-25.
Earlier, Australia's batsmen had little trouble on the relatively flat MCG wicket amassing 5-305 from 50 overs.
The star was Hughes who was making his one-day international debut. Despite having already played 20 Test matches and scoring three five-day centuries for Australia, it was the first match in coloured clothing for his country for Hughes, and he made a statement.
He became Australia's first one-day player to score a century on debut on his way to making 112 from 129 balls with 14 boundaries.
Captain Bailey also did well making 89 from 79 balls with David Hussey chiming in with an unbeaten 60 from 34 delivers to help Australia to the massive total.
All of Sri Lanka's bowlers went for some stick with Dilshan's 0-17 from four overs coming at the best economy rate of 4.25.
Despite his outstanding Big Bash League form for the Melbourne Stars, Lasith Malinga took just 1-61 from his 10 overs with Kulasekara, Mathews and Ajantha Mendis the other single wicket-takers.
Game 2 of the five-match one-day international series is on Sunday at the Adelaide Oval.