Wales will face France in the last eight next weekend after scoring four second-half tries to seal top spot in Pool D.
Shaun Edwards is optimistic Jonathan Davies will be fit for Wales in next weekend's quarter-final.
Wales head coach Warren Gatland declared "the door is not shut" for quarter-final selection ahead of their last Pool D game.
Dan Biggar, Josh Adams and Jonathan Davies all suffered injuries as Wales qualified for the World Cup quarter-finals by beating Fiji 29-17.
Josh Adams' hat-trick helped Wales secured a quarter-final spot at the Rugby World Cup with a 29-17 victory over Fiji, who were eliminated.
Warren Gatland revealed James Davies told him his opportunity at the Rugby World Cup was long overdue after being picked to face Fiji.
Wales have made two changes for their clash against Fiji at the Rugby World Cup.
There are only three survivors from the Wallabies side that lost to Wales for Saturday's crucial clash against Uruguay.
A big victory against Australia will count for little if Wales cannot also beat Fiji and Uruguay, Warren Gatland acknowledges.
Michael Hooper was frustrated to see Australia's poor first half cost them despite a stirring fightback against Wales.
Michael Hooper was frustrated to see Australia's poor first half cost them despite a stirring fightback against Wales.
Wales held firm under second-half pressure from Australia to record an impressive four-point victory on Sunday.
Wales clung on to beat Australia in a key Pool D clash at the Rugby World Cup with Warren Gatland suggesting previous teams would have lost.
Australia have repeatedly got the better of Wales at recent Rugby World Cups, but that changed in a hard-fought tussle on Sunday.
Wales meet Australia in a huge clash at the Rugby World Cup and Michael Cheika had a few choice words about Reece Hodge's ban.
Michael Cheika has made changes for Australia's Pool D blockbuster against Wales in Tokyo on Sunday.