Michael Clarke aims to win back the Ashes and top Test ranking

Michael Clarke says his Australia still have plenty to do if they want not only to win back the Ashes from England but also to become the world's top Test team.

Australia took a 2-0 lead in the five-Test series following a 218-run trouncing of England in the second Adelaide Test on Monday and are poised to retrieve the Ashes they lost in 2009 should they win the third Test in Perth starting Friday.

The Australians have proved dominant on the usually pacy WACA wicket with victories against England in their last six Tests there. England's only win in Perth came in 1978.

Captain Clarke urged his players to keep grounded as they look for one more victory to seal the series in the remaining three Tests in Perth, Melbourne and Sydney.

"I think we have to be realistic. That's our second Test win the past 12 months and that is not acceptable as an Australian Test team so our feet are certainly well and truly cemented on the ground," he said.

"There's a lot of work for us to do to get back to being the number one team in the world and that's our goal."

Australia are currently ranked fifth on the International Cricket Council rankings behind number one South Africa, with England third, and Clarke cautioned against over-expectations in Perth.

"It's obviously exciting that we're going to a ground that we feel so comfortable playing at," he said.

"But in saying that I have also experienced some defeats in my career in Perth so I'm more concerned about making sure we play the same brand of cricket that we have played so far in this series.

"I don't think it matters the conditions we play in, if we continue to play the brand that we have played.

"The positive is, we know the conditions and guys like Mitchell Johnson, Ryan Harris and Peter Siddle love bowling when there is a bit more pace and bounce, but I think the main focus is making sure we play the same brand and we're as well prepared as we were for this Test."

Clarke described Johnson, who has been man-of-the-match in both Test wins, as having the "X-factor".

Johnson took seven for 40 to destroy England in the first innings and has taken 17 wickets in the series at 12.70.

"He has always been an X-factor, with bat and ball. He's as good an athlete in the field as you'll see," Clarke said.

"Mitch has always had that. It's just about working out how to use him best in your team.

"Our attack right now really complements each other so it allows Mitch to be used the way I feel is best for our team.

"He's been our new-ball bowler, he's bowled first-change, he's bowled 12-over spells. Whatever's required, he can do that. He's been outstanding."

Clarke said Australia's two comprehensive wins had their origins in the last series in England in July-August, which they lost 3-0. (Related: Must fix Ashes, demands Cook)

"In our opinion it's not a fluke that we have won the first two Test matches. It's hard work that we put in in the UK and we thought we were so close but we didn't get over the line and we were disappointed not to have success in England," he said.

"So we as a team believe the work we have been putting in for a long period of time, now we're seeing some results."