ST JOHN'S, Antigua (AP) _ Australian skipper Ricky Ponting feels the defending World Cup champion team will improve further by playing challenging games like Sunday's Super 8s contest against England.

Seeking to become the first country to score a hat-trick of World Cup wins, Australia continued its impressive form to defeat England by seven wickets in what Ponting described as the stiffest test faced in the tournament by the reigning champion after some easy victories.

England was going well at 164-2, but lost momentum as the Australian bowlers struck back after 30 overs. Losing its way, England was bowled out to 247 runs and Ponting's 86 then boosted Australia to 248 for three with 16 balls to spare.

Australia's win was its third triumph in as many Super 8s games and sixth successive victory starting from the preliminary round. It had outplayed all previous opponents by big margins.

``Today has been our biggest test in this tournament, England played well and took the initiative away from us for a while,'' Ponting said.

``The challenging, hard hit-out today should make us better going forward.''

Australia now leads the Super 8s table with eight points, two more than second-placed New Zealand and Sri Lanka.

Winners of the 1999 and 2003 World Cups, Australia made up for its three successive losses to England in a limited-over tri-series in February. Those defeats included two finals of the Australian tri-series that gave England a surprise one-day title _ its first in a decade.

Australia's winning spree in the current event had drawn comparisons with its undefeated run to the title in the 2003 World Cup.

Ponting said his team of 2003 did run into some stiff matches, citing the games against England and New Zealand where the Aussies lineup managed to survived defeats.

``We've not had that sort of test yet and this group is in really good shape,'' Ponting said.

Ponting complimented his bowlers for bouncing back to restrict England to a modest total.

``As a captain, I feel I used the bowlers well, but there's still scope for improvement,'' he said. ``We've not played our best cricket yet.''

Ponting said claiming eight wickets for 83 runs in the last 20 overs was a terrific effort by his bowlers.

``That's where the game changed for us today, keeping England down to that score was a very good effort by the whole bowling group,'' said Ponting, adding that Australia would otherwise have ended up chasing around 280 runs.

``I felt they'll go a bit further than they did. We could have taken some risks, but we summed things up and played as we had to win the game.''

Pacemen Shaun Tait, Nathan Bracken and veteran Glenn McGrath claimed three wickets apiece with Tait's 3-41 spell securing him the man-of-the-match award.

``It's great to see younger guys working hard on their game and getting us the results,'' said Ponting.

``If we keep executive our plans for long periods of time and put the opposition under pressure, things will turn our way.''