Australia were dramatically beaten by the Asian minnows in a 50-overs per side match in Cardiff in 2005, a defeat that preceded their Ashes series reverse against England.
Bangladesh off-spinner Mohammad Mahhmud Ullah took four for 37, removing Australia's top four batsmen, and then made 31 not out in an innings where Shakib Al Hasan made 54.
But Ricky Ponting's men had too many runs for their opponents after piling up 219 for six in their 20 overs.
Watson led the way with 52 off just 23 balls including three sixes and six fours and together with wicket-keeper Brad Haddin (47) put on exactly 100 for the first wicket after Ponting won the toss.
But both openers fell in the space of three balls to Mahmud Ullah.
The off-spinner went on to have Andrew Symonds caught at short third man and Ponting taken by the wicket-keeper.
Tamin Iqbal gave Bangladesh a blazing start, taking 18 off Nathan Bracken's first over and Shakib continued to give his side hope with a 25-ball fifty, featuring two sixes and six fours, before mistiming a catch to Ponting off fast bowler Brett Lee.
From then on something like normal service was resumed and in the end Australia won by a comfortable margin with left-armer Johnson leading the attack in an innings where both Lee and Bracken took two wickets apiece.