Ronan O'Gara opened the Irish account with a penalty in the 15th minute and then swopped penalties with Elton Flatley to leave it 11-6 with a minute and a half to go to the break.
Then Ireland, attacking inside the Aussie 22, were being awarded a penalty only for Shane Horgan to foul, the penalty was reversed and Horgan and Mat Rogers were yellow-carded.
It might have been worse because Australia countered in injury-time of that opening half and it needed a last ditch Peter Stringer tackle to deny Stephen Larkham.
John Kelly came out at the start of the second half in place of the injured Denis Hickie and after John Hayes was penalised for coming in from the side in the 45th minute Flatley edged the Wallabies further ahead (14-6).
At this stage the next score was always going to be crucial. O'Gara missed with a penalty but then the Wallabies imploded when Larkham threw a quick line-out into Joe Roff who knocked-on five metres from his own line. Ireland probed right and left and it was the sheer class of Brian O'Driscoll who squeezed over in the left-hand corner. That brilliance was complimented by O'Gara who converted from the touchline and then it was a case of game on.
The Aussie struck back with venom but Ireland defended through eight phases for the concession of just three points - a Flatly penalty (17-13) - and it was them who would have gained in confidence for that resistance,
Malcolm O'Kelly went off temporarily (blood injury) to be replaced by Donncha O'Callaghan, followed by Maggs(for similar treatment ) who had to be replaced by Eric Miller but Ireland survived this set-back period and almost scored at the following end when they ran a penalty in a move that ended with Horgan knocking-on over the line from an O'Gara cross-field kick.
But incredibly it was the Irish who began to up the pace and take the game to the Wallabies. Again a awarded a kickable penalty they opted for the scrum and were just held out but O'Driscoll took a snap drop-goal and there was just a point in it with 13 minutes remaining.
By now the Irish were on fire and the Wallabies very much on the rack
David Humphreys was brought on with ten minutes to go in a switch that almost paid dividends when his drop-goal attempt went wide by the width of a coat of paint.
Ireland: G Dempsey; S Horgan, B O'Driscoll, K Maggs (E Miller temp), D Hickie (J Kelly); R O'Gara (D Humphreys), P Stringer; R Corrigan (M Horan), K Wood, J Hayes; M O'Kelly (D O'Callaghan), P O'Connell; S Easterby, K Gleeson, A Foley (E Miller).
Australia. M Rogers; W Sailor, M Burke, E Flatley, J Roff; S Larkham, G Gregan; B Young, B Cannon, B Darwin; D Giffin, N Sharpe; G Smith, P Waugh, D Lyons.
Referee - Paddy O'Brien.