Marcos Ayerza has acknowledged that Argentina will have to play at their highest level if they are to overcome Australia at the Rugby World Cup.

The two Southern Hemisphere nations collide in next weekend's semi-final at Twickenham, having navigated past Ireland and Scotland respectively.

Australia required a last-gasp penalty to book their place in the final four, while Los Pumas fared far better when running in four tries in their match on Sunday afternoon.

Speaking to Sports Mole after his side's 43-20 win in Cardiff, Ayerza said: "Australia are playing very good rugby. Their tactical game is good and their scrum is doing very well - we know it will be tough.

"The Wallabies are the Wallabies when it comes to the World Cup, so we have huge respect for them. But we know that if we play at our best then anything can happen."

Argentina's previous highest victory over Ireland prior to this afternoon came in 2007 when the two sides met in Buenos Aries.