Winger Wendall Sailor made the breakthrough for the Wallabies in the first half, using all his strength to score the first try of the tournament.
Argentina were able to cross the line themselves in the second half through Ignacio Corleto, before Joe Roff scored Australia's second try soon after.
Poor kicking from Argentinean fly-half Felipe Contemponi cost his side lots of points, and meant Australia were never really under pressure.