Unlike in their fortunate quarter-final victory over Scotland at this venue last weekend, however, they didn't lose it completely. In Ashley-Cooper they have a surpreme finisher, but the Pumas made too many errors at critical moments to capitalise on their chances.
In trying to play an expansive game, they got their strategy wrong. Instead of trying to run the ball and putting themselves under pressure, they should have played a territory-based game like the All Blacks in their 20-18 victory over the Springboks the day before.
Their scrum had the Aussies in trouble in the second half, and despite the Wallabies' improvement in this area recently, it is one area of vulnerability the All Blacks will want to exploit. Prop James Slipper, in particular, had a difficult afternoon.
Steve Hansen's desire to see the two teams bash each other up ahead of next Sunday's match was fulfilled. There were Argentina players were strewn across the pitch throughout and Aussie loose forwards Scott Fardy and David Pocock had blood streaming from their faces.
The Pumas were all but gone at halftime. Ten points in arrears without inspirational captain and hooker Agustin Creevy, who walked injured from the field, the Argentines had to cope with the sinbinning of lock Tomas Lavanini and the fact that the Wallabies were taking all their chances.
Ashley-Cooper's tries in each corner, and Rob Simmons' try from an intercept, put an enormous amount of scoreboard pressure on the Pumas, who looked over-eager from the start, a sure-fire way to make mistakes in a sudden-death match.
The big Pumas supporting contingent in the crowd didn't like many of referee Waynes Barnes' decisions and they often had a point. Barnes was determined to yellow card Lavanini for not using his arms in a tackle on Israel Folau - TMO Ben Skeen was unsure - and he spotted a knock-on late in the half when the Pumas were hot on attack that few others in the crowd saw.
It added up to a lot of frustration and the crowd let him know their feelings on halftime when Barnes jogged off to a chorus of boos.
Ashley-Cooper's try late in the second half sealed it for the Australians, but the Argentines kept trying for that elusive try to the end, roared on by a passionate crowd. It didn't quite come, but the tournament has been better for their involvement.
The All Blacks have an extra day to prepare for the final against an Australian team already battered from the Pool of Death. How much did this semifinal take out of them? We'll find out next Sunday.
Australia 29 (Adam Ashley-Cooper 3, Rob Simmons tries; Bernard Foley 3 cons, pen)
Argentina 15 (Nicolas Sanchez 5 pens)
Halftime: 19-9
- By Patrick McKendry at Twickenham
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