Sri Lanka defeated Australia by eight wickets in the second final of the tri-nation Cricket series in Adelaide.Chasing 272, the visitors crossed the target with 5.4 overs to spare. Sri Lankan openers Mahela Jayawardene and Tilakratne Dilshan took a full toll of a wayward Australian bowling attack. Dilshan was the first to pass 50 and went on for his second century of the tournament before Dinesh Chandimal and Kumar Sangakkara guided the visitors home.The third final will be played at the same venue tomorrow.Brief Scores:Australia 271 for six in 50 overs.Sri Lanka 274 for two in 44.2 overs.