Adam Ashley-Cooper scored a hat-trick of tries as Australia waltzed into a record-equalling fourth Rugby World Cup final after beating Argentina 29-15 in the second semi-final at Twickenham on Sunday.
The Wallabies, world champions in 1991 and 1999 and runners-up in 2003, will play their southern hemisphere rivals New Zealand - also in the final for the fourth time - back at Twickenham on Saturday.
The nervous Pumas leaked two early tries to Rob Simmons and Ashley-Cooper, but were battling for equilibrium when referee Wayne Barnes showed no mercy for Tomas Lavanini's misjudged low tackle on Israel Folau and showed him a yellow card.
David Pocock transformed Australia's breakdown and defensive zeal, denying the ever-ambitious Pumas any tries before Ashley-Cooper's late third score sealed a World Cup final meeting against the All Blacks.
A helter-skelter start turned harem scarum for Argentina when a nervy Nicolas Sanchez forced an inside ball, telegraphing his intentions in the process.
Wallabies lock Simmons latched on to the cut-back pass and galloped home to hand Michael Cheika's men the ideal opening within two minutes.
Sanchez and Juan Martin Hernandez then worked Marcelo Bosch clean through the midfield before Argentina forced a penalty in Australia's 22.
Poise recovered, Sanchez stepped up and slotted the kick to cut Australia's lead to four points.
But the occasion continued to rock the Pumas with Santiago Cordero knocking on in the process of tapping a mark he was trying to take quickly.
Australia struck straight from the scrum, Argentina's backline all flying inwards, gifting Ashley-Cooper an unopposed run-in for the second try, which Bernard Foley converted to push Australia 14-3 up after 10 minutes.
Argentina won a fine breakdown penalty but fluffed their five-metre lineout before Sanchez slotted his second three-pointer after a scrum penalty.
However, the points came at a price as the Pumas' lost danger man Juan Imhoff to injury.
Referee Barnes then incurred the wrath of the Argentina fans by sin-binning Lavanini for a no-arms tackle on Folau.
Lavanini could reasonably have expected a penalty for his indiscretion, but the addition of a yellow card after lengthy television review appeared harsh to the blue and white fans in attendance.
Somehow Argentina won a scrum penalty despite the loss of Lavanini. However their scrum then lost another key component as captain Agustin Creevy hobbled off after 30 minutes.
Despite their early heroics, Sanchez was turned over after a risky half-break from his own 22, and the Wallabies punished the Pumas.
Folau almost powered clear, before Matt Giteau floated a beautiful pass out to Ashley-Cooper, who slid home for his second try and the Wallabies' third.
Still Argentina pressed, Sanchez landing his third penalty of the half, before Cordero shredded the Wallabies' line to race close. However, Hernandez could not find full-back Joaquin Tuculet when halted just shy of the line, and Australia escaped to the break 19-9 up.
Foley missed a regulation penalty at the start of the second half before Argentina's attacking lynchpin Juan Martin Hernandez limped off the field.
Argentina then bulldozed Australia off their own scrum again, forcing a penalty that Sanchez landed with ease before Foley responded with a penalty of his own.
Argentina punted one kickable penalty to touch, then won another penalty from the lineout before Sanchez opted to take the three points.
With just a converted try between the teams Argentina continued to press, refusing to be broken by either their slow start or the Wallabies' stubbornness.
However, Australia's ferocious defence stood up to another test.
And after soaking up so much pressure across the course of the half, from a blindside lineout break the Wallabies struck.
Drew Mitchell exploited half a yard on the left wing to scoot through the line before scything n off the flank.
Mitchell evaded four cover tackles before flinging a desperate pass out to the right flank. Somehow the ball bobbled backwards and Ashley-Cooper scooped up and scooted home for his hat-trick score - the try that killed off the Pumas' resistance.
The Pumas battled on, throwing the ball about and attacking with skill, verve and excitement, but ultimately fell short of the line.
Australia now roll on into the final, where they will aim to dethrone defending champions the All Blacks in a clash between the two best sides in the competition, while Argentina face South Africa in a battle for third place.
