The only team to beat the Boks so far this year are the British & Irish Lions in the third Test in Johannesburg and it is going to take three drubbings at the end of their Tri Nations campaign to stop them from winning the title for a third time and ending four years of All Black dominance.
But du Preez says his side won't be resting on their laurels - especially as the last time they met the Wallabies in Brisbane they went down 49-0.
"You can never get to the top and say you can't do better. I don't think we're at the top yet - there's still a lot to come from this team," said du Preez..
"We have a few areas to work on and improve and this team is young enough to go further. I always believe there is room for improvement.
"To get five points in Australia is just great. We used exactly the same tactics as before, it's just we had more opportunities to run the ball.
"We just need to keep the momentum we created in the first three matches at home going and get a bit better this weekend. The last time we were in Brisbane we lost 49-0, so it would be great to go there and win the title."
It was du Preez's try that set the Springboks on the way to their fourth successive triumph and within 10 minutes the visitors were 12-0 ahead. Centre Jacque Fourie got the second and two tries from Bryan Habana had secured a bonus pint by the 52nd minute.
Trailing 22-6 at the break the Wallabies looked down and out, but they fought back to score three tries in the second half to creep back to take a bonus point. However, it was their third successive defeat and even their faintest hopes of competing for the tile have now gone.
Scorers: Wallabies: Tries: Matt Giteau 2, Lachlan Turner; Cons: Matt Giteau 2; Pen: Matt Giteau 2.
Springboks: Tries: Bryan Habana 2, Fourie du Preez, Jaque Fourie; Cons: Morné Steyn 3; Pens: Morné Steyn 2.