Australia set up a World Cup final against New Zealand as an Adam Ashley-Cooper hat-trick helped them edge past Argentina 29-15 at Twickenham on Sunday.
The Wallabies went over three times in the first half and despite the excellent goal-kicking of Nicolás Sánchez, Ashley-Cooper's third, following a magnificent break from Drew Mitchell, sealed the win.
Australia will have to be better to beat the All Blacks, with their discipline a real issue, but in Bernard Foley and Matt Giteau they have two distributors of the highest order, while David Pocock was back to his incomparable best as he ruled at the breakdown.
A disastrous first half for the Pumas began with an intercept try after barely a minute, Rob Simmons grabbing Sánchez's inside pass before showing his pace to run in from the 22.
After a Sánchez penalty cut the deficit, Australia went over again through Ashley-Cooper, with a wide pass from Foley carving up the Pumas.
Argentina lost a wobbly Juan Imhoff to injury, closely followed by Tomás Lavanini to a marginal yellow card. Skipper Agustín Creevy joined them on the sidelines, clearly not 100 per cent having only just been passed fit this week.
Against 14 men, Australia were clinical, Giteau putting Ashley-Cooper over for his second, and despite a third penalty from Sánchez, the Wallabies led 19-9 at the break.
Two more penalties from Sánchez, to one from Foley made it a one-score game heading into the last ten minutes, but Mitchell then produced a moment of magic as he shrugged off a succession of tackles from his left wing, and delivered a scrappy final pass to create Ashley-Cooper's third and kill off the Puma challenge.
With just a minute on the board Australia were 7-0 up as Argentina paid the price for too much adventure in their own half. After Mitchell had narrowly failed to hang on to one interception, Simmons showed his handling skills to stick out a mitt and collect Sánchez's inside ball before racing over from the 22. Foley converted from in front to give the Wallabies a dream start.
Argentina came straight back when Juan Martín Hernández perfectly delayed his pass to send Marcelo Bosch clean through. For a second it looked like he might have the pace to cross but Foley came across to make the cover tackle. The Wallabies infringed, allowing Sánchez to get his team on the board with a penalty, but Hernández was shaken up in the move after a big hit as he passed.
Australia had clearly done their homework though and scored a simple try from a perfect training ground move. Spotting that the Pumas keep their wingers narrow in defence, Foley threw a perfect wide pass that sent Ashley-Cooper over on the right after a scrum opposite the posts in the Argentinian 22. Foley converted from the touchline and Australia led 14-3 after just ten minutes.
It could have been even worse for Argentina when another fantastic wide pass from Foley opened up the Pumas again. Israel Folau fed Tevita Kuridrani, who burst through, but Santiago Cordero brought him down and the support was too far away to deliver the final pass.
Argentina were trying to play too much rugby in their own half, while Pocock showed his worth for the Wallabies with a number of a turnovers at the breakdown.
The Pumas lost Imhoff to injury with barely quarter of an hour gone, their top scorer clearly knocked out in a huge collision and replaced by Lucas González Amorosino.
Midway through the half they looked to have an opportunity to get back in contention, but a five-metre lineout and maul was easily dealt with by the Wallabies. From the resulting scrum, Argentina earned a penalty which Sánchez converted from out wide to cut the deficit to eight.
Having been overwhelmed early, Argentina really needed to build on that penalty, but instead they were reduced to 14 men when Lavanini was sin-binned for a no-arms tackle on Israel Folau, Wayne Barnes earning jeers from the Pumas-dominated crowd for his decision.
Australia turned down a shot at goal a minute later as they went to their maul, but Argentina defended it well and earned a scrum.
Still, things weren't going to plan for Argentina and it got worse when Creevy, who had been a doubt this week, had to leave his teammates after half an hour, replaced by Julián Montoya.
A minute later Australia were in again, taking advantage of their extra man to send Ashley-Cooper over once more. A couple of missed tackles on Folau allowed him to get in behind. Argentina held initially but Australia showed their class with Giteau's long miss-pass giving the winger the easy finish, on the left this time. Foley pulled the conversion wide but Australia led 19-6.
An offside from Sekope Kepu with five minutes left in the half allowed Sánchez to knock over his third penalty of the afternoon and make it a ten-point deficit.
And they could have been back to within a score on the stroke of half-time when Cordero went clean through. He managed to find Hernández outside him, but the centre's pass didn't go to hand.
The second half could have started perfectly for Australia, but Foley was off-target with a penalty after Fardy had stolen the ball at the restart.
Hernández, who had been struggling since the early Bosch break, finally left the field three minutes into the half, but Argentina took advantage of a big scrum to cut the deficit to seven with Sánchez's fourth penalty.
It was quickly cancelled out by Foley, making no mistake this time after Fernández Lobbe couldn't resist and handled in a ruck.
The game was really opening up, with Argentina looking dangerous, particularly thanks to one break from Joaquín Tuculet. After Australia were penalised at a maul, Sánchez cut the deficit to seven once again.
Another break from Amorosino almost had Argentina in, with Tuculet on his shoulder, but Australia held firm before the ball went loose in a ruck.
When a poor kick from Tuculet gave Australia a shot at goal from 45 metres out with 15 minutes to go, they curiously turned it down, and a loose lineout allowed the Pumas to clear.
The game was still on a knife-edge, but that changed when Mitchell intervened and ended the game as a contest setting up Ashley-Cooper's treble. Foley converted and there was no way back for Argentina.
Man of the match: Australia comprehensively won the breakdown battle, and it was in large part thanks to the returning David Pocock. Back from injury, he made turnover after turnover and took advantage of Argentinian naïvety in the first half. Hat tip to Ashley-Cooper for his well-taken hat-trick.
Moment of the match: Argentina were somehow still in it with ten minutes to go. Drew Mitchell then stepped up, broke down the left, cut inside and found Adam Ashley-Cooper for his hat-trick.
Villain of the match: Nothing nasty to report.
Pens: Sanchez 5
Yellow Card: Lavanini
Tries: Simmons, Ashley-Cooper 3
Cons: Foley 3
Argentina: 15 Joaquin Tuculet, 14 Santiago Cordero, 13 Marcelo Bosch, 12 Juan Martin Hernandez, 11 Juan Imhoff, 10 Nicolas Sanchez, 9 Martin Landajo, 8 Leonardo Senatore, 7 Juan Martin Fernandez Lobbe, 6 Pablo Matera, 5 Tomas Lavanini, 4 Guido Petti, 3 Ramiro Herrera, 2 Agustin Creevy (c), 1 Marcos Ayerza
Replacements: 16 Julian Montoya, 17 Lucas Noguera Paz, 18 Juan Figallo, 19 Matias Alemanno, 20 Facundo Isa, 21 Tomas Cubelli, 22 Jeronimo de la Fuente, 23 Lucas Gonzalez Amorosino
Australia: 15 Israel Folau, 14 Adam Ashley-Cooper, 13 Tevita Kuridrani, 12 Matt Giteau, 11 Drew Mitchell, 10 Bernard Foley, 9 Will Genia, 8 David Pocock, 7 Michael Hooper, 6 Scott Fardy, 5 Rob Simmons, 4 Kane Douglas, 3 Sekope Kepu, 2 Stephen Moore (c), 1 James Slipper
Replacements: 16 Tatafu Polota-Nau, 17 Toby Smith, 18 Greg Holmes, 19 Dean Mumm, 20 Sean McMahon, 21 Nick Phipps, 22 Matt Toomua, 23 Kurtley Beale
Venue: Twickenham Stadium, London
Referee: Wayne Barnes (England)
Assistant Referees: Jaco Peyper (South Africa), George Clancy (Ireland)
TMO: Ben Skeen (New Zealand)