Opener Tillakaratne Dilshan flayed a match-winning 106 which ensured Sri Lanka achieved their 272 run target with 34 balls to spare at Adelaide Oval.
The Lankans cruised to 2-274 from 44.2 overs in reply to Australia’s 6-271 which featured tons to Michael Clarke and David Warner.
There are question marks over Clarke’s fitness for Thursday’s Adelaide decider. The Australian captain limped the through the latter stages of his sterling 117 from 91 balls, hobbled by tightness in his left hamstring.
Clarke fielded until the 38th over of the emphatic Sri Lankan run chase before leaving for treatment – he has a history of back-related hamstring injuries and only returned from a right hamstring strain last Sunday.
Clarke’s century and an even 100 by Warner underpinned an Australian total aided by six dropped catches by the tourists.
But Dilshan and Mahela Jayawardene (80 from 76 balls) made light work in the third highest successful one-day run chase at Adelaide Oval.
The duo plundered a 179-run opening partnership from just 165 balls to give their side its fourth win over Australia in six clashes this series.