Australia underperformed in all three facets of the game in an ODI loss to West Indies, but it was sloppy fielding that frustrated Steve Smith the most in St Kitts.
Smith (74) and Usman Khawaja (98), both promoted one spot up the order because of David Warner's broken finger, took control of the tri-series clash in a 170-run stand.
A 300-plus total beckoned but Australia struggled to find the boundary late and finished on 7-265, a total the hosts overhauled with four wickets in hand and 4.2 overs remaining.
The hosts rocketed to 0-40 after four overs, with Johnson Charles and Andre Fletcher sharing a breathtaking 74-run stand.
Both openers were reprieved by Khawaja, who came agonisingly close to making his maiden ODI century, but was responsible for the low point of a fielding performance that surprised Smith.
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"We were sloppy with most of the things we did in the field," the skipper said.
"This isn't the standard the Australian cricket team sets ... we didn't field like an Australian side.
"We want to be the best fielding team in the world, so we've got a lot of work to do to get to that mark."
Smith, who lost the toss, sensed the problem was "an attitude thing".
"The guys just seemed a little bit flat," he said.
"It's hard to put a finger on it, I guess it's just each individual looking at themselves in the mirror and making sure we have that attitude to go out there and get the job done.
"We made pretty costly errors pretty early in the game, they cost us a fair bit in the end."
Fletcher was on four when he chipped a ball to mid-on, where Khawaja was unable to hold a low catch.
Khawaja then made a mess of a chance in the deep, which came when Charles was on 36.
Fletcher scored 27, while Charles was trapped lbw by Adam Zampa on 48.
Marlon Samuels top-scored with 92, his man-of-the-match knock ending after three consecutive sixes off legspinner Zampa.
Smith lamented his side's ineffectual bowling, which underlined the importance of rested spearhead Mitchell Starc.
"We started really poorly with the ball ... we were a fair way off our lines and lengths," he said.
"It's obviously nice to have him (Starc) as much as you can. He's obviously just coming back .. after an injury so we're trying to take care of him."
As for Australia's batting, Smith felt they were "short by 20 runs".
The result means the race to the tournament final in Barbados on June 26 is wide open.
"It's always a confidence booster to beat Australia .. it means we're moving in the right direction," West Indies coach Phil Simmons said.
If South Africa defeat West Indies in the next match it will mean each side has two wins from four games.
Australia have a six-day break before they face the Proteas in Barbados at 3am AEST on Monday.
