Marvan Atapattu struck 82 and Arjuna Ranatunga, the captain, shrugged off injury to hit an unbeaten 45 as Sri Lanka reached their target of 211 with three deliveries of their 50 overs to spare. A late slump in which five wickets tumbled for 35 threatened Sri Lanka's victory ambitions, but they were not to be denied after Australia made 210 for 9 in their 50 overs.
Ranatunga, limping noticeably after straining a calf muscle while fielding on a soft Bellerive Oval, needed a runner but his 61-ball innings ensured his side's success after they slipped from 163 for 3 to 198 for 7. The leg-spinner Shane Warne, who finished with 3 for 45 off his 10 overs, and the pace bowler Glenn McGrath, with 1 for 33 off his 10, did the damage.
Sri Lanka had been put on course for victory by a 116-run second-wicket partnership off 71 balls between Atapattu and the opener Romesh Kaluwitharana, who struck 54. Atapattu's 82 came off 121 balls in 168 minutes and included six fours.
England lead the tri-nation series on eight points, with Australia on four and Sri Lanka, who have a match in hand, on two. The top two qualify for the best-of-three finals.
Australia went into the match without Ricky Ponting, who was dropped after being involved in a fight outside a Sydney nightclub. Adding to their problems were injuries to Steve Waugh and Michael Bevan.
Waugh was unable to field after suffering a recurrence of the hamstring injury that kept him out of the early matches of the series. He felt a sharp twinge as he was running between wickets during his innings of 20.
Team officials said it was in the same area of his left leg as his old injury and he was almost certain to miss Australia's next two matches of the series, against Sri Lanka on Sunday and England on Tuesday.
Bevan suffered a minor strain to his right groin, saying he felt it while batting and then aggravated it in the field. He was replaced by the Tasmanian bowler, Damien Wright.
Ranatunga was thrilled withthe win. "I thought we batted really well, then panicked a little in the middle. I was a bit worried towards the end," he said.
Earlier Mark Waugh and Darren Lehmann posted half-centuries in Australia's modest total. Waugh top-scored with 65 and Lehmann made 51 in the most significant partnership of the innings - 93 for the third wicket. Both survived chances as the Sri Lankans missed numerous catches, but once they were parted Australia's batting struggled.Reuse content