Australian players are itching to get their World Cup campaign started after their first opponents on Thursday, Fiji, began their tournament with a gallant effort against England at Twickenham.
Fiji pushed England hard and trailed by only 18-11 in the second half.
England's bench helped the hosts push away late in the game to secure a bonus point win.
With tier 1 nations almost feeling like endangered species, Australia saw enough of Fiji to know they'll be hunting them with confidence in Cardiff.
"I think it's going to be a tough game," Wallabies lock Will Skelton said. "They threw a lot at England - some of it came off, some of it didn't. I assume they will bring the same team against us.
"It's going to be fast in the forwards, damaging carriers, and in the backs you've got guys like Nems [Nemani Nadolo] and Benny Volavola who really shift the ball and have a great kicking game. It's going to be a good game."
Asked if it was England stepping up or Fiji's fitness failing them late, Skelton said it was "maybe a bit of both" and pointed towards Australia's strong second-half efforts this year as being potentially important at Millennium Stadium.