From man-of-the-match Cian Healy through to full-back Rob Kearney and the replacements, Ireland produced a level of performance that left the Australians struggling for clean ball and the platform to put their dangerous backs into space.

It was a defence-dominated encounter, with very few try-scoring chances, but it held the raucous crowd at Eden Park spellbound and Ireland's clever, gritty play saw them deservedly pull nine points clear of the Wallabies.

The result ends Ireland's long wait for a landmark win on Southern Hemisphere soil, and blows the Rugby World Cup wide open with Declan Kidney's men now on course for a quarter-final meeting with the second-placed side in Pool D.

Paul O'Connell, who carried a huge workload in the pack once again, spoke of his satisfaction with how the game panned out for Ireland but is keenly aware that this is only week two of the tournament.

"Today we played to our potential. We haven't won anything...it's just a pool game. All the games from now on in are big games for us," he said.

The poise that Australia showed in dismantling Italy in the second half of their pool opener was missing early on, their efforts not being helped by the withdrawals of key flanker David Pocock, who has a back complaint, and an ill Stephen Moore.

Ireland set about their task with renewed energy and focus, and improvements from the win over the USA were evident in the opening exchanges. The game was 50 seconds old when Ireland won a penalty, having held up Pat McCabe in the tackle and forced a turnover.

Chants of 'Ole, Ole' rose up out of the Auckland stadium, the many Irish fans in the stands warming to the sight of Healy, Sean O'Brien and Jamie Heaslip rumbling forward with ball in hand.

The Wallabies got in to disrupt an Irish lineout, four minutes in, and from the scrum Quade Cooper found some space outside the 22. Rob Kearney's high tackle on Kurtley Beale gave young winger James O'Connor the chance to open the scoring, but his difficult kick drifted past the left hand post.

Australia's tails were up though, the dangerous Beale gathering a high ball under Kearney's nose and Rocky Elsom, the former Leinster flanker, beginning a good phase of continuity in the Irish 22. Tatafu Polota-Nau was involved twice as they got to within a couple of metres of the try-line.

A subsequent scrum had to be reset and World Cup debutant Healy was penalised for collapsing it. O'Connor made no mistake with the close range kick, edging his side ahead in the 11th minute.

A textbook tackle by O'Connell on James Horwill allowed Healy to quickly get over the ball and force a penalty near the Australian 10-metre line. Although Sexton had the distance, his kick edged away to the right and wide.

Ireland were back on the offensive in no time, Sexton sending up a garryowen which Kearney did brilliantly to collect. Brian O'Driscoll took his team into the 22 and after Elsom coughed up a penalty, the Irish number 10 squared things up on the scoreboard.

Tommy Bowe gained ten metres having fetched Cooper's restart. Angled running, crisp passing and better ball protection were all features as Ireland suddenly took the game to Australia.

The backs and forwards combined impressively before Sexton, with the benefit of a penalty advantage, slotted over a drop goal.

Kearney gathered a high ball under pressure from Beale, the liveliest of the Australian backs, and the 'choke' tackle tactic paid off again leading to a solid scrum, which became an area of strength for Ireland for much of the game.

Australia asked some questions of Ireland's defence and Keith Earls answered them with a thumping man-and-ball tackle on McCabe. Referee Bryce Lawrence was playing a penalty advantage for offside though, and O'Connor kicked the Wallabies level in the 24th minute.

O'Driscoll and Gordon D'Arcy tackled tigerishly as Cooper tried to unlock the Irish defence over halfway. A rush of blood saw Jamie Heaslip give away a penalty at the next ruck, only for O'Connor to narrowly miss the target.

Sexton suffered his second miss from a penalty, after pressure from the Irish scrum forced Sekope Kepu to infringe.

But Ireland remained on the front foot, their sheer aggression typified by a late Stephen Ferris-inspired drive that shunted Will Genia back into the Australian 22.

There were some neat touches from D'Arcy, who had to go off with a tight hamstring, and the ever alert Eoin Reddan as the second half got underway, with Rory Best increasing his influence in terms of the set pieces, ball-carrying and leadership.

In the 48th minute, Australian captain Horwill went offside at a ruck as Ireland gained some momentum amid a series of drives. Sexton accepted the gift, knocking his right-sided kick over for a 9-6 scoreline.

D'Arcy's injury prompted the introduction of Ronan O'Gara with Sexton moving to inside centre, and there was obvious concern for Wallaby players and fans alike when a strong scrum yielded another penalty for Sexton to line up.

The Dubliner's strike was a clean one but came back off the left hand upright and O'Driscoll went agonisingly close to gathering the high bouncing ball under the shadow of the posts.

Moments later, a powerful hit by Healy on Cooper prevented the Australian playmaker from launching a long range counter.

Disciplined defending kept the Australians at bay as they threatened coming up to the hour mark, O'Connell's challenge forcing Cooper into throwing a forward pass and shortly afterwards the same player was well wrapped by O'Driscoll and Earls.

Ireland briefly lined out with a centre partnership of Earls and Andrew Trimble while O'Driscoll had a blood injury treated.

Young scrum half Conor Murray also came on to win his fourth cap, and sterling scrum work again from Healy, Best and Mike Ross led to O'Gara extending the advantage to 12-6.

Genia probed around the fringes as Robbie Deans' men remained dangerous, although there was much more potency in Ireland's advances.

Australia could not deal with a steepling kick from O'Gara, the ball breaking for Kearney to regain possession and Ross, having juggled O'Connell's pass, was stopped just three metres short of the whitewash.

As rain fell from the Auckland sky, the Tri Nations champions gave way in a scrum close to their posts and O'Gara mopped up with his second successful penalty, crucially nudging Ireland more than a converted try clear.

Using their greater experience and big match nous, Kidney's side were able to hold firm in a frantic final few minutes.

Ashley-Cooper threatened out wide and it took a tremendous tackle from a diving O'Brien to prevent Genia from touching down.

Just when it looked like Australia might open up the Irish defence with a quick tap penalty, Cooper's backhanded pass was gobbled up by Bowe who raced away out of the 22 and over halway only for O'Connor to close him down and tackle him into touch before the try-line.

In a tense and breathless climax, Murray had a try chalked off for an earlier infringement and Australia raided back over halfway. Nevertheless, there was no way back for them and Ireland, having recaptured some of their best form, were just too good on the night.