Sri Lanka needed eight runs from four balls but Australia survived to win the third match by 5 runs.
Perth: Australia won their second consecutive tri-series match with a tense five-run win over Sri Lanka at the WACA Ground on Friday.
Following their opening win over India last Sunday at the Melbourne Cricket Ground, Australia had some anxious moments in the final over.
Sri Lanka, chasing 232 for victory, looked out of the match after slumping to 180-9 in the 45th over. But a 36-run partnership between vice-captain Angelo Mathews (64 runs off 76 balls) and tailender Dhammika Prasad (15 not out off 11) lifted Sri Lanka to within sight of a late victory.
Sri Lanka needed 18 runs off Mitchell Starc's final over, but the task became a more realistic eight off four balls after Mathews hit a four then a six straight down the ground. Needing six off the final two balls, Mathews went for the big hit to win but got underneath the short delivery too much and was caught by Dan Christian in the deep.
Sri Lanka were all out for 226 in 49.5 overs, after bowling out Australia for 231 with five balls to spare, suffering their second straight loss in the tournament.
Australia captain Michael Clarke, who hit 57 runs, claimed the wicket of Dinesh Chandimal (37) at an important time. Spinner Xavier Doherty also played a key role, taking 2-24 from 10 overs.
Allrounder Dan Christian, who scored 33, took two wickets.
Australia will be looking to win their third tri-series match in a row when they play India (1-1) at the Adelaide Oval on Sunday.
Sri Lanka were in control at 61-1 in the 15th over before paceman Clint McKay ran out Kumar Sangakkara for 22. After playing McKay to short square leg, Sangakkara slipped mid-pitch after being sent back by batting partner Tillakaratne Dilshan. That was all the time needed by McKay, who scooped up the ball and threw down the stumps in the one motion to find Sangakkara well short of his crease.
Dilshan didn't last much longer before edging Ryan Harris through to the wicketkeeper for 40.
Earlier, five Sri Lanka bowlers took two wickets each. In temperatures that nearly reached 40 degrees Celsius, Clarke was the only Australia batsman to notch a half-century as Sri Lanka's bowling attack thrived in the Perth heat.
Mathews snared the key wickets of David Warner and Clarke, while Lasith Malinga, Prasad, Nuwan Kulasekara and spinner Sachithra Senanayake also had two wickets each.
Clarke combined with Christian (33) to lift Australia from 130-5 to 186-5, but their dismissal within four runs of each other - followed soon after by the demise of Ryan Harris - left Australia at 192-8. Tailenders McKay (25) and Starc (14) ensured Australia posted a competitive total.
McKay was the last man out on the first ball of the final over when Lahiru Thirimanne - running with the flight of the ball - snared a diving catch just inches short of the square leg boundary.
Brothers Mike (23) and David Hussey (27) failed to make the most of their starts for Australia.