Shane Watson hit a record 15 sixes on his way to making the highest one-day innings by an Australian as Bangladesh were crushed by nine wickets.
The 29-year-old, who also hit 15 fours, scored 185 off 96 balls - beating Matthew Hayden's previous total of 181 made against New Zealand in 2007.
"I got a bit of luck," said Watson, who beat West Indies' Xavier Marshall's record of 12 sixes.
"I had no idea what the sixes record was. I didn't want to run too much."
Former captain Ricky Ponting, who struck the winning runs in a 170-run partnership for the second wicket, hailed his batting partner's performance.
"My job was easy, I just let Shane do what he was doing," said the 36-year-old.
"Shane's now played a couple of great innings in last few months. Today's effort was amazing.
"It hasn't sunk in yet. We'll sit back at end of careers and reflect on how amazing that was."
Watson also recorded the sixth-highest one-day score when he struck 161 against England in January this year.
Ponting joined Watson at the crease with the scores on 62-1 after Brad Haddin lost his wicket when he was caught by Mahmudullah off the bowling of Shakib Al Hasan.
The opener, who along with Ponting helped Australia reach 100 inside 15 overs, smashed Suhrawadi Shuvo for four sixes in the 22nd over on his way to helping Australia to their second successive victory over Bangladesh to tie up the three-match series win.
Earlier, Watson also took a wicket and made two catches as the home side laboured to 229-7 from their 50 overs.
The Tigers could only manager 62 in 20 overs and were reduced to 88-5, partly thanks to left-arm paceman Mitchell Johnson, who removed openers Tamim Iqbal  and Imrul Kayes  before eventually finishing with figures of 3-54.
Mushfiqur Rahim [81 no] and Mahmudullah  added some respectibility to the total with a 79-run stand before the latter was out lbw to Watson.