Australia secured a spot in the semi-final of the World Rugby Under-20 Championship after beating Ireland in Argentina.
They managed a hard-fought 47-14 win at Racecourse Stadium in Rosario.
With two wins out of two, Australia cannot be knocked off the top of Pool B.
Defending champions France are also unbeaten in Pool A, having eased past Wales 32-12, while the hosts thrashed Fiji 41-14.
In Pool C, New Zealand and South Africa both secured their second victories.
The Kiwis defeated Scotland 52-33, while South Africa scored eight tries in a 48-20 demolition of Georgia.
England managed a late penalty against Italy to win 24-23, but still missed out on a place in the semis.
Pool action continues on June 12.