Belfast: Australia openers David Warner (84) and Joe Burns (69) both made runs before Ireland fought back in the lone one-day international in Belfast on Thursday to hold the world champions to 222 for six in 40.2 overs.
Rain brought Australia's innings to a premature close in what was their first match at this level since beating New Zealand in the World Cup final in Melbourne in March.
With rain having already delayed the scheduled start and forcing a further reduction in overs during Australia's innings, Ireland were set a revised target of 195 to win in 27 overs under the Duckworth/Lewis method.
That in turn became 181 in 24 overs after yet more rain halted Ireland's reply with the hosts 27 for two after 6.2 overs.
The match was set for an intriguing finale after Ireland, the leading non-Test nation, had made a fine recovery in the field after being forced to go into the game without big-hitting Kevin O'Brien because of a hamstring injury.
Australia, with Steven Smith leading the team for the first time in his new role as captain, following the retirement of Michael Clarke, chose to bat on a good pitch and Burns, on his ODI debut, and Warner justified his decision.
They put on 139 for the first wicket, with both batsmen compiling half-centuries, but Ireland hit back with six wickets for 85 runs to give the home crowd plenty to shout about.
The first 10 overs powerplay, though, was dominated by Australia as they scored 80, which included nine fours and two sixes, with Craig Young receiving the harshest treatment, his third over going for 17, including three consecutive fours by Burns.
The Queenslander was the first to his fifty, from 45 balls and two deliveries later, Warner brought up his half century from one ball fewer, both openers then having an identical boundary count of six fours and a six.
Young thought he had the first wicket when Burns, on 61, edged to the wicketkeeper, but the television umpire ruled that it was a no-ball and the new cap's innings continued.
Only for another four overs, however, as Young got his man for the addition of just eight more runs, a mistimed pull going safely into the gloves of Niall O'Brien, getting his chance behind the wicket in place of Gary Wilson.
Warner hit the next ball for six but that was to be the last boundary for 11 overs as Ireland took control, reducing the tourists to 172 for four with Warner caught at deep mid-wicket for 84, George Bailey bowled by Tim Murtagh for one and Glenn Maxwell brilliantly caught low down to his right by O'Brien for just two.
Ireland claimed the big scalp of Smith, caught behind for 21 and just before the rain arrived Mitchell Marsh found the hands of Murtagh at long-off.
Brief scores
Australia- 222 for 6 (Warner 84, Burns 69)
Ireland - 157 (O'Brien 45, Coulter-Nile 3-13)
Result - Australia won by 23 runs (DLS method)
MOM - David Warner (Australia)