Thisara Perera snared a five-wicket haul as Sri Lanka restricted Australia to 239 on Wednesday in the series-opening limited-overs international.
After winning the toss and opting to bat, Australia was coasting at 85 for one until Perera took three wickets in eight balls, starting by dismissing Michael Clarke for 27 in the 17th over.
The Sri Lankan paceman removed Brad Haddin (49) and Cameron White, for a first-ball duck, on consecutive balls in his next over as Australia slipped to 88-4. He finished with figures of 5-46.
Mike Hussey defended the hat-trick ball, then guided Australia's comeback with an unbeaten 71.
Australia skipper Ricky Ponting was missing the match to attend a family funeral.