Pathum Nissanka drove Sri Lanka to a six-wicket victory over Australia in Colombo as the young batsman made his first ODI century.

The 24-year-old Nissanka was out for 137 just as Sri Lanka approached the winning line, but by that point it was too late for Australia.

Chasing down Australia's 291-6, Sri Lanka reached their target with nine balls to spare, posting 292-4 to achieve their highest successful run chase against Australia in ODIs.

Captain Aaron Finch made 62 for Australia, with Alex Carey weighing in with 49 and Travis Head cracking three sixes in his 70 not out.

Yet it proved well within Sri Lanka's reach as Nissanka shared a stand of 170 for the second wicket with Kusal Mendis, before Mendis retired hurt on 87 at the end of the 38th over, seemingly troubled by a leg muscle injury. It ranks as the highest second-wicket stand by a Sri Lanka pair against Australia in ODI games.

Australia won the opener to the five-match series at the Pallekele International Stadium on Tuesday, but Sri Lanka got back on level terms with victory at the same ground in the Kandy suburbs on Thursday.

Both were rain-affected games, but the wet weather held off at the R Premadasa Stadium and the home crowd relished the sight of Nissanka and Mendis setting about a largely impotent bowling attack.

There was a late wobble as Dhananjaya de Silva (25), Nissanka and Dasun Shanaka (0) were dismissed, with David Warner taking a terrific one-handed catch on the run and over his shoulder to dismiss the century maker, but Australia's hopes were soon extinguished as they slipped 2-1 behind in the series.

Nissanka shows he belongs

In 14 previous ODIs, Nissanka had a best score of 75. In his first nine matches at this level, he scored a not-so-grand total of 86 runs; however, he found his feet with two half-centuries against Zimbabwe in January, and after making 56 followed by 14 in this series, he turned it on in grand style on Sunday.

Happy hunting ground

Sri Lanka's men have now won three of their last four ODIs against Australia at the R Premadasa Stadium, and nine of their last 12 at the venue against all opposition. This win, following the victory on Thursday, means Sri Lanka have won back-to-back ODIs against Australia for the first time since January 2013.