An aggressive approach to a modest run chase saw Australia win the fourth ODI by 6 wickets to take an unbeatable 3-1 lead in the five-match series.
Powered by belligerent knocks from Aaron Finch and George Bailey, Australia eclipsed the Sri Lankan total of 212 in short order.
Sri Lanka weren't helped by the loss of skipper Angelo Mathews, who was injured while batting and despite returning to complete his innings did not take the field with his team, who were led by Dinesh Chandimal.
The hosts attempt at setting a decent total was beset by a steady flow of wickets.
Dhananjaya de Silva stood out with his well played 76 off 87 balls but only Angelo Mathews made a fist of trying to stay with him.
John Hastings was in devastating form picking up career-best figures of 6/45.
Finch came out in the mood to do some damage and tied the record for the fastest half-century by an Australian batsman.
The opener fell soon after reaching the milestone, and Australia lost a flurry of wickets to Sachith Pathirana.
The left-armer got Finch (55), Khawaja (0) and Warner (19) in the space of two overs to leave the tourists reeling.
A century stand between Bailey and Travis Head would take the game away from Sri Lanka though.
Bailey continued with the same aggressive intent that marked Finch's knock and by the time Head fell for 40, Australia needed just 16 to win with ample time remaining.
Wicketkeeper, Matthew Wade would help Bailey guide Australia over the line with 19.4 overs remaining.
Bailey ended the match on an unbeaten 90 while Pathirana finished as the pick of the Sri Lankan bowlers with figures of 3/37.
Australia have now secured the ODI series after taking a 3-1 lead in the five-match series.