Michael Clarke's [ Images ] team took an unassailable 4-1 lead in the seven-match series after hitting 249 in 49.3 overs and then bowling out the visitors for 198.
"The boys are very excited. It's great to come back after losing the Ashes test series and it shows a lot of courage," skipper Clarke told Australia's Channel Nine.
"We still see a lot of room for improvement so the next couple of games are very important for us. The feeling in the camp is fantastic."
England, however, self destructed when they still had plenty of overs remaining and two well-established players batting.
Pietersen again succumbed to a rush of blood to the head when he misread a slower John Hastings delivery and spooned the ball to Lee at mid-on to leave his team 95 for four.
Eoin Morgan [ Images ] (two) also threw away his wicket when he smashed Steve Smith straight to Mitchell Johnson [ Images ] at long off while Bell chopped Hastings on to his stumps to leave England 103 for six.
Shane Watson [ Images ] then dismissed Paul Collingwood [ Images ] (18) and Chris Woakes (eight) in his first over, the 33rd of the innings, to all but end the run chase despite some final-wicket defiance from James Anderson [ Images ] (22 not out) and Steve Finn (35).
"We thought 250 was very chaseable but fair play to Australia, they bowled well with the new ball and got early wickets and it was hard for us to keep the momentum up without losing wickets," said England captain Andrew Strauss [ Images ].
"Australia have deserved to win this series but we still have two games to go and need to finish with a bit of a bang heading into next month's World Cup."
Earlier, Clarke ended his poor run of scores with a half century while the tail provided a late flurry to help the home side post a good total despite man of the match Woakes claiming six for 45.
Clarke, who had been under pressure, combined for a 65-run partnership with David Hussey [ Images ] (34) for the fifth wicket.
He then needlessly charged Woakes in the 41st over and top edged a simple catch to Strauss on 54.
Clarke's dismissal left Australia 190 for six but Smith (24 not out), Johnson (16) and Hastings (13) combined well in the latter stages to set up a victory charge that will give them confidence heading into the World Cup.
The match was also used to help raise money following recent flooding.
The floods have swamped the eastern seaboard of Australia, killing 35 people, crippling coal mines, ruining crops, damaging infrastructure, destroying homes and causing an estimated A$5 billion (US$4.98 billion) in damage in Queensland alone.
More than A$6 million (US$5.96 million) was raised from the game, with the final figure to be matched by the Australian federal government.
"It makes you really very proud to see the way Australians have got out and responded, from a local barbie (BBQ) ... to some of our biggest companies in the country," Prime Minister Julia Gillard [ Images ] told Australia's Channel Nine.