Doncaster Rovers gave new manager Dean Saunders the perfect start thanks to a late winner from John Oster.
Oster hit his first goal in 18 months to end Rovers' 19-match winless streak following the exit of Sean O'Driscoll.
The winner came when Oster picked up possession in his own half before unleashing a stunning 30-yard shot past Palace goalkeeper Julian Speroni.
Palace had a lot of early possession with Mile Jedinak going close but once Oster scored it was all Rovers.
The victory was just the boost the South Yorkshire club needed after Friday's events which suprised many supporters.
The appointment of Saunders came just two days after chairman John Ryan had publicly backed the then Championship's longest-serving manager.
Saunders brought in Jon Parkin, Brian Stock and Richard Naylor while Billy Sharp, who damaged ankle ligaments on the opening day of the season, was a surprise inclusion on the bench.
Palace recalled seven players after the midweek Carling Cup win over Middlesbrough and they had the better of an uneventful first half, with Australia international Jedinak volleying just over from the edge of the area in the 50th minute.
Saunders made a double substitution with Sharp and Slovakian forward Milan Lalkovic replacing Parkin and winger James Coppinger.
The changes did not appear to have much affect until Oster took possession and burst into the Palace half before firing an unstoppable shot into the bottom left-hand corner.
Doncaster striker James Hayter was off target from the edge of the penalty area as the home side chased a second and Oster went close with another rocket, this time from 20 yards, soon after.
By this time it was all one-way traffic and with Palace offering little in attack, Hayter went close to firing a second in the 86th minute, but his close-range shot flew the wrong side of the post.