The Wallabies may have won their past 10 matches against Wales, but lock Dean Mumm said that would count for nothing when the teams clash at Twickenham on Sunday morning.
With a quarter-final against Scotland likely for the winner, compared to a clash with South Africa for the loser, the Pool A top-spot decider is absolutely crucial.
Mumm said the recent record against the Welsh may be 10-0, but that was irrelevant and improving every game was the key.
"This weekend is an early finals game and the way we go about it, it's a very big element - we take this game very seriously going forward," Mumm said.
"So the way we improve, the way we approach, the way we prepare for it is very important."
Wales assistant coach Rob Howley said the team that can "master the moments and have accuracy in the last 20 minutes of the game" could emerge as the winner.
"Looking back over the last seven years it's the same old story," Howley said. "Over the last 10 minutes, they have killed us on many occasions."
While Australia and Wales will play in the quarter-finals regardless of the result, the tournament is over for Pool C minnows Georgia and Namibia
Georgia won the final game 17-16 to book its place in the 2019 World Cup in Japan, provided the All Blacks beat Tonga tomorrow morning.
That likelihood was enough for Georgia veteran Levan Datunashvili to say it was party time.
"I think we'll start with a few beers to warm up, and then afterwards we'll see," the 32-year-old said. "We're in England so we have to try a little bit of whisky as well."
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