Australia suffered early blows when they lost fly-half Quade Cooper and full-back Kurtley Beale to injury inside 20 minutes.
Cooper could face six months out with suspected knee ligament damage, while Beale appeared to suffer a recurrence of hamstring trouble that sidelined him for last weekend’s semi-final defeat against tournament favourites New Zealand.
But Australia still had enough in the tank to deny Wales their best World Cup finish for 24 years. Back then, the roles were reversed, with Wales triumphing to push Australia into fourth place.
Coveted third-place finish
This time round, wing Shane Williams marked his final World Cup appearance with a try – albeit a lucky one when a blatant forward pass was missed – and full-back Leigh Halfpenny also touched down.
James Hook and Stephen Jones kicked a penalty apiece, with Jones also converting Halfpenny’s score, but the third-place finish Wales coveted eluded them.
Australia manufactured tries by centre Berrick Barnes and number eight Ben McCalman, while Barnes also drop-kicked a goal and wing James O’Connor kicked eight points.
Wales missed suspended skipper Sam Warburton, plus injured pair Rhys Priestland and Adam Jones.
They will return home tomorrow after losing three of their seven World Cup games – by a combined total of five points – but Wales are guaranteed to be a top-four seed for the 2015 tournament hosted by England.