Ireland coach Mike Ruddock has already turned his attention to next Sunday's clash with Fiji after a stunning victory in south Brittany in the U-20s World Cup.
They were made sweat it out to the end after coughing up two soft tries, but it would have been a travesty if they were beaten.
Ruddock said there is no danger of them taking anything for granted following the superb victory at Stade de la Rabine in Brittany.
Ireland face Fiji on Sunday where a win will set them up for a clash against New Zealand next Thursday with a potential semi-final place up for grabs. The Baby Blacks hammered Fiji 59-6 last night.
Ruddock said their thoughts have turned to Fiji on Sunday.
"It was very hot there, the boys lost a bit of weight in that heat. We'll regroup and we'll have a look at Fiji now. We won't spend too much time celebrating," he said.
Australia may have been much bigger than Ireland, but Ruddock's men were more skilled from handling to precision tackling with strike runners emerging from all angles.
Tighthead Adam Boland gave a magnificent display. And Conor Joyce, a flanker of some class manifested the difference in skill levels between the sides. Australia, who apparently gave the Irish players plenty of lip in the tunnel, threw their weight around but a seventh minute Tom Daly penalty put Ireland into a lead they never surrendered.
The opening try came after 26 minutes, prop Boland came in at a good angle in midfield and when it went wide on the right, he used Rory Scholes and Adam Byrne as decoys, before he diving over in the corner. Daly slotted the conversion.
But the Wallabies struck back before the interval. UJ Seuteni landed a penalty and then lock Thomas Staniforth got over from a scrum to leave it 10-8 at the break.
Seuteni missed a penalty to put Australia ahead, but Ireland took control and two Daly penalties opened up a 16-8 after 67 minutes.
But then Ireland were caught for a breakaway try from Alex Northam with the conversion from Luke Burton leaving it 16-15 with seven minutes left.
It looked as if a superb opening victory was going to turn into a nightmare as Australia piled on the pressure, but the Irish scrum and defence held firm and Daly sealed a famous win with his fourth penalty.
Ireland – R Scannell (Munster); A Byrne (Leinster), T Farrell (Leinster), T Daly (Leinster), R Scholes (Ulster); S Crosbie (Leinster), L McGrath (Leinster) (capt); P Dooley (Leinster), G McGuigan (Exile), A Boland (Connacht); P Timmins (Leinster), J Donnan (Ulster); C Joyce (Ulster), J van der Flier (Leinster), R Murphy (Munster). Reps: D Leavy (Leinster) for Murphy (36), R Furniss (Exile) for Boland (54-64 blood), B Byrne (Leinster) for McGuigan (72), E Byrne (Leinster) for Dooley (72), D Leader (Connacht) for Scannell (75), S McCarthy (Munster) for Timmins (80).
Ref – L Pearce (England).
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