The positions have since been swapped with Australia ranked ninth to Ireland's 10th, but only an impressive victory in the Group B match at Premadasa Stadium on Wednesday will convince many that the missing trophy can possibly be added to the Australians' cabinet.
Ireland beat Pakistan in 2007 and England in 2011 at the 50-over World Cups, but Australia captain George Bailey said Tuesday he is not worried about his opponent's giant-killing reputation.
Australia has won the 50-over World Cup a record four times and reached the final of the 2010 World Twenty20, going down to old foe England.
"I think it has taken a little while for Australia to take Twenty20 seriously,'' Bailey said. "At the end of the day, Australian cricket has one trophy that's not in its cabinet and that's the Twenty20 World Cup. That's something we are aware of and we'd like to rectify.
"We focused really hard on what we do well and how well we play our best cricket. I think if we play our best cricket everything will work out OK.''
Ireland captain William Porterfiled feels his team has a good chance against an Australian team that is going through a period of transition.
"We believe we can win the game, it's pretty simple as that as far as we are concerned,'' he said. "I think we can push anyone on any day.''