Australia have swept aside their four opponents in the tournament so far and look set to add momentum to their bid for an unprecedented title hat-trick against a side ranked ninth in the one-day international rankings.
"They might be the world champions but they are not unbeatable," Bangladesh captain Habibul Bashar said. "If we get everything together, we think we can do it."
Bangladesh scored a shock win over India - who were later eliminated - to qualify behind Sri Lanka from Group B, reaching the second round for the first time in three attempts.
That upset surprised fewer experts compared to their stunning victory over Pakistan in the 1999 tournament.
Bangladesh also upset Australia in 2005 in Cardiff and Bashar believes his team can become the first to restrict Australia to less than 300
LOWEST TOTAL
Australia's lowest total so far has been 322 and only the weather - it rained heavily on Friday afternoon - looks like stopping Ricky Ponting's team.
"It's long gone and forgotten about as far as we are concerned," Ponting said referring to the Cardiff loss. "We just didn't play at our best that day.
"The cricket you've seen us play the last few weeks would indicate that tomorrow, the way we are going at the moment, that we should be able to play cricket good enough to win this game."
Bangladesh's performances have contrasted with the 2003 World Cup when they failed to win one game.
They have stuck with the same five bowlers for the group games, including three left-arm spinners Mohammad Rafique, Saqibul Hassan and Abdur Razzak.
The seven-week World Cup culminates in the April 28 final in Barbados.