James Anderson becomes England's all-time one-day wicket taker.
Champions trophy: Ian Bell chimes in for first round against rivals Australia
Bell made 91 on his Warwickshire home ground, to the delight of a capacity 25,000 crowd, as England posted 269 for six after captain Alastair Cook won the toss.
Bell also shared a second-wicket stand of 111 with county colleague Jonathan Trott (43) in the first of at least 26 matches, including the upcoming Ashes series in England, across all formats against arch-rivals Australia between now and February 2.
Australia pegged England back before an unbroken seventh-wicket stand of 56 between Ravi Bopara (46 not out) and Tim Bresnan (19 not out) bolstered England's total.
However, a target of 270 proved beyond an Australia side still without captain Michael Clarke, following the recurrence of the star batsman's long-standing back injury.
"It was nice to get a decent score," said man-of-the-match Bell in a post-match interview. "I have been getting a lot of 30s and getting out so I was pleased to give us a good platform. I have enjoyed opening - it's nice to play some shots at the top of the order."
During Australia's 221 for nine, spearhead seamer James Anderson (three for 30) became England's outright most successful one-day international (ODI) bowler, taking the one wicket he needed to surpass the record of 234 wickets he had shared with Darren Gough.
Australia' George Bailey made 55 as they at least put the embarrassment of their 65 all out in Tuesday's warm-up defeat by India behind them, but the stand-in captain said the batsmen were once again at fault.
"We couldn't get any momentum and well done to England - they restricted us well," said Bailey. "The scoreline flattered us a little; it was the batting which let us down."
However, this loss left Australia - bidding for a third straight Champions Trophy title - with a mountain to climb if they were to qualify for the semi-finals out of a Group A also featuring New Zealand and Sri Lanka, who meet in Cardiff today.
Australia's reply suffered an early setback when David Warner (nine) was well caught by diving wicketkeeper Jos Buttler off Stuart Broad. Shane Watson (24) fell next, caught by Cook off Tim Bresnan.
Mitchell Marsh became Anderson's record-breaking victim, caught by Eoin Morgan. Anderson then made it two wickets for two runs in six balls when Matthew Wade was caught behind.
"He's a great bowler, he just keeps getting better and better, we're lucky to have him," Cook said of Anderson.
Bailey pressed on to a 62-ball fifty but when he holed out off spinner James Tredwell, Australia were all but beaten at 151 for seven. James Faulkner finished on 54 not out, but his runs came too late.