Villa went down 1-0 in a tight clash against Palace at Selhurst Park.
Jason Puncheon broke claret-and-blue hearts with a 76th-minute shot which condemned Paul Lambert's men to a fourth consecutive setback.
Villa had previously defended resolutely, doggedly resisting everything the Eagles could throw at them.
But this result means they are still looking anxiously over their shoulders as they prepare for the final five games of the season.
The scoreline might have been heavier, too, Tony Pulis's revitalised side twice hitting the woodwork.
Yet Villa almost grabbed a dramatic late equaliser in a fine move involving two of their subs.
Marc Albrighton's lofted pass was headed on by Grant Holt, and Andi Weimann's close-range flicked was brilliantly tipped away by Julian Speroni.
Palace made the more assured start, although the home side's early forays posed no great danger for the Villa defence.
Puncheon met Yannick Bolasie's deep cross with a hooked left-foot volley which sailed harmlessly wide of the far post.
As Villa began to establish a foothold, Ashley Westwood's fine cross flicked off Damien Delaney's head for a corner before Ciaran Clark ventured forward for a close-range header which striker Cameron Jerome cleared from the goalmouth as Speroni prepared to gather the ball.
Then Holt climbed above his marker to meet Westwood's centre from the right with a header which went behind, while Westwood's attempted side-footer from 25 yards was charged down by Mile Jedinak following a flowing move by Lambert's men.
But there was huge relief for Villa in the 36th minute when a well-worked Palace free-kick left Bolasie with an open target seven yards out.
Thankfully the midfielder firing wide as he was challenged by Holt.
Bolasie appealed strongly for a penalty but referee Howard Webb waved play on.
That was the signal for another spell of home pressure, sub Maouane Chamakh heading wide from Adrian Marippa's cross before Bolasi sent another header straight at Brad Guzan.
On the stroke of half-time, Delph's deflected 25-yarder was held by Speroni, who also did well to clutch a powerful Gabby Agbonlahor drive four minutes after the interval.
In the 54th minute, though, the Eagles should have been in front.
Bolasie's clipped shot was palmed away at full stretch by Guzan but only as far as Caremon Jerome, who looked a certain scorer but somehow contrived to lift the ball against the underside of the bar from a couple of yards.
There was another close call on the hour mark, Jason Puncheon's fierce 25-yard drive skidding just inches wide with Guzan beaten.
Seven minutes later, referee Webb pointed to the spot after Clark had diverted Bolasi's cross back to Guzan, with Palace's players and fans calling for hand ball.
But Villa's players alerted the official to a linesman who pointed out that the ball had actually struck Clark's chest.
But Villa's defence finally cracked when Bolasie broke down the left to deliver a cross which evaded Ron Vlaar.
Puncheon brought the ball under control and despite being closely marked by Ryan Bertrand, the midfield man turned sharply for a low shot which went in off the foot of the post.
Villa's response was a fine Westwood pass which Matt Lowton controlled on his chest before sending a left-footer just wide, but in the 85th minute Puncheon almost grabbed a second when he cut inside and fired against the outside of the post.
Even so Villa were desperately unlucky not to draw level when Weimann was denied by Speroni's crucial late save before Clark had a stoppage-time effort deflected away from goal.
Palace: Speroni; Mariappa, Dann, Delaney, Ward; Puncheon, Dikgacoi (Chamakh 18), Jedinak, Ledley, Bolasie (Parr 81); Jerome (Murray 75). Unused subs: Hennessey, Ince, Gayle, Gabbidon.
Villa: Guzan; Lowton, Clark, Vlaar, Baker, Clark, Bertrand (Weimann 82); El Ahmadi (Albrighton 82), Westwood, Delph; Holt, Agbonlahor. Unused subs: Steer, Bennett, Sylla, Bowery, Tonev.