Australia are on course to secure a quarter-final with Scotland after building a narrow half-time lead against Wales in the Pool A decider at Twickenham.
Dan Biggar kicked the Welsh into an early lead after some pressure from Warren Gatland's men almost brought a try in the opening moments.
Minutes later, captain Sam Warburton tried to extend his team's lead as he powered towards the Australia line before finding Gareth Anscombe, who was met by a fierce tackle from Sean McMahon.
The Wallabies' first foray into the Wales 22 only came in the 22nd minute as Drew Mitchell pierced the gain line, but was quickly bundled into touch by two defenders.
Australia levelled the scores through the boot of Bernard Foley and went ahead after winger Liam Williams was adjudged to have been off his feet at the breakdown.
Wales quickly restored parity after Stephen Moore failed to move away from the tackle area before Toby Faletau's eagerness to steal the ball also saw him penalised.
Biggar had the chance to bring Wales level at the break but steered his kick wide of the posts, before Matt Giteau tried his luck from inside his own half and failed to get enough distance on his attempt.
