The Wallabies have won the last eight encounters between the sides and return to the Millennium Stadium in the final clash of the Dove Men Series.
They have left Wales broken hearted by claiming last-gasp wins on the last three occasions and Folau reckons another triumph would leave mental scars ahead of the 2015 World Cup where the rivals are drawn in Pool A alongside England.
“If we win this weekend we will have a bit of an edge on them psychologically,” said Folau.
“Going into that game at the World Cup we will know we have done a job on them in the past.
“That can help us later down the track but our main focus is on this week.”
And Folau is well aware of the threat the Wallabies face in Cardiff having played his part in the Test series against the British & Irish Lions.
Warren Gatland has named 11 Lions tourists in his starting XV and Folau knows none more so than George North.
The giants enjoyed a running battle during the series which the Lions won 2-1, with both players scoring sensational individual tries and North carrying Folau over his should in the second Test one of the most iconic images of the tour.
And the former Rugby League and Aussie Rules ace is relishing going up against the Wales back three which also contains Lions Leigh Halfpenny and Alex Cuthbert.
“There’s still a bit of spice in it, especially after the Lions,” added Folau.
“A lot of the Welsh boys were involved in that series. It’s still clear in our minds. It’s going to be a big contest this week.
“George’s a great player – I enjoyed playing against him in the Lions series. He’s one of the danger men we have got to look out for on Saturday night.
“There’s a bit of a joke that goes around in Australia. There was a muck around advert for a new backpack with myself on George’s back.
“He’s a strong lad and I just ended up in an awkward position. It’s all fun, it’s good.
“It’s what the fans want to see and, as a player, you want to test yourself against great players like him. I enjoyed the challenge.
“Alex Cuthbert is another great player. He’s another guy we have to watch and, obviously, Halfpenny at the back is not a big guy but gets through a lot of work and inspires his team.
“Discipline has a big part to play on Saturday night. We have to make sure we don’t give him a chance to kick goals.”