In a game of very little quality Chris Iwelumo's stunning strike on 74 minutes was enough to give Bristol City the win at Selhurst Park.
For Palace it was a performance to forget as they struggled throughout the game to find the same levels that earned them the win against Sheffield United three days before.
In the first half City were allowed to control the half, and but for a lack of class in the final third to add a finish to their possession, should have had the lead going into the break.
On eight minutes Bradley Orr was allowed a lot of time and space to try his luck from 35 yards, but the distance proved far enough for Speroni to get into position and make the save.
Palace then had a decent shout for a penalty on 12 minutes when a Johnny Ertl volley smashed into the hands of a Bristol defender, but the referee didn't hesitate in waving it away. On reflection it was point blank and would have been harsh on the visitors.
From there though the home side struggled to find any sort cohesion within their ranks, and a series of unforced errors suffocated every foray into Bristol's half and allowed the visitors to keep up the pressure.
Fortunately though for Palace Bristol's finishing was disappointing from their perspective.
On loan striker Iwelumo twice had good opportunities to give his side the lead and both times he should have done much better.
His first arrived when Shaun Derry lost the ball in the middle to Cole Skuse and the midfielder played in the Scotland international just outside the box. Twenty five yards from goal he squared up Matt Lawrence and decided to shoot quickly, but it was a tame effort that Speroni gathered comfortably.
His second was probably a little more difficult, but was still a gilt edged chance in a half where chances were at a premium. This time it was a Liam Fontaine assist as his low cross into the box was met by the Scot with a half volley that ballooned up and over the bar.
An indicator of the room Palace were allowing Bristol arrived on 21 minutes when Paul Hartley showed a good turn of pace inside his own half and carried the ball to the edge of the Palace box before a challenge was made. Thankfully for the Eagles his finishing displayed the same qualities as his team mates and he screwed it harmlessly wide of Speroni's post.
Palace's first and only meaningful effort on goal arrived on 28 minutes when Calvin Andrew turned neatly on the edge of the box and aimed a shot to the bottom right corner. It took a deflection and forced Dean Gerken into the save.
The early stages of the second half promised better quality than the first, but after Iwelumo hit another effort over the bar and Alan Lee headed wide the game quickly deteriorated.
The Lee chance was Palace's best of the game. The Irishman managed to steal a yard on Lewin Nyatanga in the box and met Ambrose's lofted free kick with a header across goal that was just too angled and bounced past the post.
Ambrose then had a good chance himself when he was found by Clyne on the right, but after working some space on the edge of the box with a series of stepovers he blasted wastefully over the bar.
From then on Bristol created the best chances. The tenacious Orr worked hard to get to the byline on 61 minutes and pulled the ball back for Skuse, who met it with a sweet half volley that was blocked by a host of Palace bodies.
Orr was then presented with a great chance himself when a ball from the right was allowed to run right the way across the box and he directed it to the top corner, but Speroni was equal to it and made the save.
In the end though it took a bit of class to separate the two sides and Iwelumo's brilliant volley from 15 yards over Speroni eventually broke the deadlock.
The Scotland international had everything to do when he received the ball with his back to goal, but he managed to swivel on a sixpence and loop a dipping effort over the Palace keeper.
Paul Hart threw on Stern John to add greater attacking threat in the Palace front line, and it almost had an instant effect when he was inches away from connecting with a low cross from the right.
But it was not enough as time slipped away and Bristol City claimed all three points.
Att: 12 844 ( Away: 609)
Palace Player subscribers can watch Paul Hart's post match press conference tomorrow morning.
Crystal Palace: 1. Julian Speroni, 2. Nathaniel Clyne, 3. Clint Hill, 4. Shaun Derry (cpt), 7. Darren Ambrose (8. Neil Danns, 68 ), 10. Nick Carle (9. Stern John, 80), 17. Matt Lawrence, 18. Calvin Andrew, 19. Alan Lee, 20. Danny Butterfield, 22. Johnny Ertl
Bristol City: 22. Dean Gerken, 2. Bradley Orr, 4. Liam Fontaine, 6. Louis Carey (cpt), 8. Lee Johnson, 10. Nicky Maynard, 11. Paul Hartley, 14. Cole Skuse, 20. Jamal Campbell-Ryce, 32. Lewin Nyatanga, 37. Chris Iwelumo
Subs: 3. Jamie McAllister, 9. David Clarkson, 15. Gavin Williams, 16. John Akinde, 17. Ivan Sproule, 30. Stephen Henderson, 31. Danny Haynes