Kevin Pietersen produced another stunning display to clinch a dramatic victory for England and continue Australia's troubled start to their Ashes tour.

Only 24 hours after suffering one of the most humiliating defeats in their history to Bangladesh and having suspended key all-rounder Andrew Symonds for breaching team rules, the world champions bounced back strongly and seemed on course for an improbable victory at sun-drenched Bristol.

But just as they seemed ready to lift the gloom by claiming a timely triumph, winter hero Pietersen stepped up with a vicious assault on Australia's highly-regarded attack to complete a three-wicket victory with 15 balls to spare.

Pietersen, man-of-the-series after scoring three centuries against South Africa during the winter, picked up where he left off then by hammering 91 off only 65 balls to snatch an incredible victory from the world champions.

England were struggled to match Australia's respectable total of 252 for nine after a succession of ill-judged shots left them struggling to keep up with the rate.

When Geraint Jones holed out into the deep the hosts had slumped to 160 for six - needing 93 runs off the final 12 overs.

But Jones' dismissal was the signal for Pietersen to launch an astonishing attack.

The 24-year-old dominated a 54-run stand off only 30 balls with Vikram Solanki, who was brilliantly run out by wicketkeeper Adam Gilchrist for 13, and left England's new hero with the responsibility to guide them home.

The South African-born Hampshire player, man-of-the-match in England's Twenty20 triumph over Australia last Monday, showed supreme confidence to bully the once-dominant world champions - hammering eight fours and four sixes in his swashbuckling innings.

His composure prevented rampant England, confidence lifted by their emphatic triumph at the Rose Bowl, sliding to an unexpected defeat after Australia gave a display which suggested reports of their demise may have been slightly exaggerated.

England enjoyed the better of the early exchanges with Steve Harmison claiming four wickets for two runs in 15 balls to leave Australia, who chose to bat after winning the toss, reeling on 63 for four inside the first 16 overs.

Australia had been given a solid platform with openers Adam Gilchrist and Matthew Hayden forging a 57-run stand with both batsmen launching Jon Lewis, making his first international appearance at his county ground, over long-on for six during an expensive three-over burst with the new ball which cost 22 runs.

His withdrawal from the attack proved the turning point for England, with Vaughan turning to Harmison with spectacular effect.

The Durham fast bowler tore through the Australian top order to establish possible psychological points ahead of the Ashes series.

Gilchrist edged behind after being surprised by extra bounce, Ponting fell to a full-length inswinger to the next delivery and although Damien Martyn was able to allow the hat-trick ball pass by his off-stump, he could not resist upper-cutting the next delivery which settled in Kevin Pietersen's safe hands at third man.

It took a stunning one-handed catch above his head from Paul Collingwood at point to remove Hayden four overs later, only for Michael Clarke and Mike Hussey to provide crucial middle-order resistance.

The pair added 105 in 20 overs with Hussey, playing only his sixth one-day international, hitting a career-best 84 off only 83 balls which threatened to take Australia to a far more challenging total.

Hussey, fully acclimatised to English conditions after starting the season as Durham's captain, hit 11 boundaries in his innings but fell at a crucial stage when he was bowled by a Harmison slower ball to earn his county colleague his first five-wicket haul at this level.

Despite reaching a respectable total, England were still regarded as favourites until Glenn McGrath reminded the healthy crowd of his presence by bowling both Marcus Trescothick and Andrew Strauss during an opening spell plagued by an uncharacteristic wide and two no-balls.

Paul Collingwood, batting at number four, also chopped on to Michael Kasprowicz and although captain Michael Vaughan batted patiently, all-rounder Andrew Flintoff and Jones holed out in the deep to ill-conceived shots which increased the pressure - and the scoring rate - on England.

Vaughan batted with determination but without urgency and when he was trapped leg before wicket by left-arm leg-spinner Brad Hogg, he had scored 57 off 92 balls and left his side needing more than seven an over to claim an increasingly unlikely victory.

His patience was rewarded, though, with man-of-the-match Pietersen's breathtaking innings continuing England's relentless winning run and maintained their stranglehold over disjointed Australia.