Two second half goals from Kevin Zefi and Alex Nolan – his first for his country - secured the victory meaning Jason Donohue’s team have now won seven out of seven internationals this season.
Ireland were the brighter of the two teams and debutant Pearse O’Brien – drafted in from Oakwood FC in Connecticut - drew a good save from Australian goalkeeper Callum Cook who then thwarted Adam Murphy on the rebound.
Nolan had a glorious chance to give his side the lead on 22 minutes when he capitalised on a mistake by Cook, but the Australian defence did well to get back and clear his effort that was heading into an empty net.
Australia had their own chance to go in front on the stroke of half-time. A mistake in the Ireland backline saw the ball fall to Sebastian Hernandez whose shot was well saved by Conor Walsh before the danger was cleared.
But it was Ireland who took the lead shortly after the interval. Zefi got wide on the left and cut in to curl a great effort into the top corner for his sixth goal for Ireland this season.
Nolan, who posed a threat throughout, almost scored shortly after the Zefi goal when he went through one-on-one but Cook stood big and pulled off another good save.
The St Patrick’s Athletic forward eventually got on the scoresheet in the 52nd minute. Taking advantage of the space behind the Australian backline he raced onto the ball and was able to slot home past the goalkeeper for his first international goal.
Ireland controlled the rest of the game but couldn’t add to their two goals.
Next up for Jason Donohue’s team is a tournament in Spain where they will face the hosts, Netherlands and Czech Republic.
Republic of Ireland: Walsh (O’Leary 50) Cowper Gray (Malone 65), Luke O’Brien (Hughes 65), Curtis (Kelly 61), Heffernan; O’Brien-Whitmarsh (Ferizaj 41), Pearse O’Brien (Murray 61), McManus (Barrett 41); Zefi, Nolan, Murphy (Tetteh 61)
Australia: Cook, Martelota, O’Donoghue, Mathie, Croucher, Hughes, Drew, Frack, Hernandez, Florez, Cefala.
Substitutes: Beach (GK), Ball, Di Pizio, Gibson, Tanddo, Skotadis, Inglese