The tourists went to stumps on night two at Sabina Park at 6-99 in their second innings, leading West Indies by 181 runs but with the game firmly in the balance.
Sam Konstas was out for a duck and his opening partner Usman Khawaja for 14, before Cameron Green offered the only firm resistance with an unbeaten 42 in a chaotic final session.
Australia's batting woes came after Scott Boland vindicated his selection at the expense of Nathan Lyon, claiming 3-34 to have the hosts out for 143.
That handed Australia an 82-run first-innings lead in their pursuit of a 3-0 sweep of the Frank Worrell Trophy, but also exposed the batters to two and a half hours under lights against a new Dukes ball.
And while the selectors appear to have got it right with the Boland call, much bigger questions loom ahead of the Ashes.
Konstas was caught playing at a ball outside off stump, taking the teenager's total return for the series to 50 runs at 8.33.
Khawaja followed four overs later when he played on to Shamar Joseph, leaving him with 123 runs at 15.37 in the four Tests dating back to Test Championship final.
This tour has been brutal for batters on both sides, and is on track to be the first three-Test series without a century scored by either team in almost 30 years.
Regardless of that, veteran Khawaja and youngster Konstas have done little to lock in Ashes selection.
Cricket Australia announced the summer's domestic schedule on Monday, with four Shield rounds before the first Test in Perth on November 21.
Runs in those games could be key for Konstas and Khawaja.
Potential replacements Nathan McSweeney, Cameron Bancroft, Matt Renshaw, Marcus Harris and Marnus Labuschagne could also make their cases.
There were some brief positives for Australia with the bat on day two.
Green has grown in confidence as a No.3 on this tour, standing tall and driving superbly as Alzarri Joseph (3-19) wreaked havoc for everyone else.
The West Australian had a difficult start to life at No.3 in the Test Championship final, but now has scores of 52, 46 and 42 not out from his past three innings.
Joseph bowled Steve Smith off the right-hander's bat and pad for five, before trapping Beau Webster lbw for 13 and edging off Alex Carey for a duck.
Carey was struck on the head first ball by Alzarri Joseph, before he charged the quick and was caught at second slip to leave Australia 6-69.
Pat Cummins (5no) was lucky not to immediately follow when he gloved Joseph down the leg side, but West Indies did not review it. There was also a missed run-out chance.
Earlier, Boland had been Australia's best with the ball as he used seam movement to remove the Windies' two top scorers in John Campbell (36) and Shai Hope (23).
The Victorian angled a ball back at a leaving Campbell to have him lbw, before nipping one back between Hope's bat and pad to bowl him.
Boland then finished the job by bowling Shamar Joseph, as the hosts lost 5-19.
Cummins and Josh Hazlewood finished with two wickets each.
"I think Nathan (Lyon) will come straight back in next game," Boland said.
"When he bowls with a pink ball, especially in Adelaide, he gets it bouncing and spinning a lot.
"It's probably going to be a one-off. I would like to play as many games as I could, especially with the other three (quicks).
"But I probably see it going back to the norm, especially once we get Greeny back bowling for the summer as well."
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