Pacemen Glenn McGrath (3-17) and Shaun Tait (3-39) reduced the match between the defending champions and the Cup debutants to a no-contest when they wrecked Ireland's top order with their opening spells.
Ireland could never recover after being reduced to 12-4 in the fifth over on a pitch having pace, bounce and movement. They were eventually dismissed for 91, a total which was too small to put pressure on in-form Australia.
The match was completed before the lunch-break as Australia raced to the target off just 12.2 overs despite changing their batting order.
Hard-hitting Adam Gilchrist (34) and Michael Hussey (30 not out) ensured an easy victory with a brisk 62-run stand for the opening wicket.
Hussey, a middle-order batsman opening the innings for the first time, got valuable batting practice ahead of his team's last two matches against New Zealand and Sri Lanka.
Both wicketkeeper-batsman Gilchrist and Hussey toyed with the Irish bowling, gathering runs with consummate ease. Gilchrist hit four boundaries in his 24-ball knock and Hussey finished the match with a six off Boyd Rankin.
Andrew Symonds, who was also promoted in the batting order, remained unbeaten with 15.
Ricky Ponting's unbeaten Australians now lead the table with 10 points from five matches, followed by Sri Lanka (8/5), New Zealand (8/5), South Africa (6/5), England (4/5), the West Indies (2/5) and Bangladesh (2/5).
Ireland, who gave a good account of themsleves in the previous Super Eights games, were overawed by the occasion for the first time as they looked extremely vulnerable against quality pace after being put in to bat.
John Mooney (23), Kevin O'Brien (16) and skipper Trent Johnston (17) were the only batsmen to reach double-figures in a brittle Irish batting display lasting just 30 overs.
The carnage began in the opening over itself when veteran McGrath brought one in sharply to rattle the stumps of Jeremy Bray. The next four overs only added to Ireland's batting woes.
Tait bowled at a lively pace on a helpful track and was on a hat-trick in only his second over when he trapped opener William Porterfield leg-before and bowled Niall O'Brien.
Wickets continued to tumble as McGrath had Eion Morgan caught by Matthew Hayden in the slips, the first four Irish batsmen contributing just two runs.
There was no respite from pace for the Ireland as McGrath and Tait continued to probe the batsmen.
Middle-order batsman Andrew White suffered a nasty blow on the helmet off a rising McGrath delivery before falling in the bowler's next over, caught by Brad Hogg at mid-off.
Mooney, Kevin O'Brien and Australia-born Johnston offered a little bit of resistance, but it was just not good enough.
O'Brien was caught by Brad Hodge off paceman Stuart Clark, who had replaced Nathan Bracken from the side which defeated England in the previous match.
Johnston dragged a Tait delivery on to his stumps to leave his side tottering at 54-7. Ireland failed to cross the 100-mark as Australia grabbed the last three wickets in quick succession.