Despite a first-ever one-day international century to stand-in skipper Mike Hussey, Australia suffered a three-wicket defeat in match four of the DLF Cup against the West Indies in Kuala Lumpur.
The Caribbean Islanders leapfrog Australia in the table ahead of their final match of the triangular series against India on Wednesday.
Australia can still make certain of a place in Sunday's final with a win against the Indians on Friday.
The West Indians' victory arrived on the back of a cultured third-wicket 151-run partnership between flamboyant opener Chris Gayle and captain Brian Lara.
Having lost Shivnarine Chanderpaul for no score and Ramnaresh Sarwan for 25 early, the stylish Gayle, once joined in the middle by Lara, passed 5000 one-day international runs on his way to a typically plundering 79 off 93 balls.
Lara, who survived a close call when the third umpire ruled him not out after reaching the 50-stand with Gayle and was also dropped on a no ball, went onto reach 87 in just 80 deliveries before he completely misjudged one from Brett Lee and was snaffled by Hussey via the back of his bat.
Hussey's plight was not helped by a relatively inexperienced bowling attack at his disposal with Ashes hopeful Stuart Clark, in particular, suffering a pair of horror spells at the hands of Gayle and Lara.
Plagued by wides and no balls, Clark - just two days after Mitchell Johnson returned 4-11 against India's top order - finished with figures of 0-87 in seven overs before being removed from the attack.
In total, the Aussies gifted 33 runs in extras as the West Indies cruised home with 16 balls to spare despite a late wobble when Wavell Hinds, Marlon Samuels and Dwayne Smith were dismissed in the final stages.
Dwayne Bravo settled the encounter by finishing with a pressurised unbeaten 37 as the West Indies' tail threatened to collapse once again.
Nathan Bracken (1-31) and Shane Watson (1-43) were the most frugal of the six Australian bowlers used while Lee returned 3-46.
In the first innings, Hussey had rescued Australia with a captain's knock of an unbeaten 109 to guide Australia to an unlikely total of 6-273.
The controlled innings - from just 90 deliveries - was his first one-day century and included 10 fours and three sixes.
Having arrived as early as the 18th over after seeing five top-order wickets slip away, Hussey and wicketkeeper Brad Haddin steadied to build an 166-run stand which started quietly but finished with a flourish.
Haddin (70 from 76 balls) played his part, posting his maiden one-day international 50 with his fourth huge six of a technically impressive innings.
Matthew Hayden had fallen one run short of a well-carved half-century in his comeback match - his first international ODI since the NatWest Challenge in England last July.
