In front of their lowest league attendance of the season Rovers made it just one defeat in ten with a 1-0 win over Iain Dowie's men.
Pedersen scored his fourth league goal of the season in a first half where chances were of a premium.
Mark Hughes made three changes from the side that faced Arsenal at the weekend. David Thompson and Garry Flitcroft were replaced by Brett Emerton and Robbie Savage, while Paul Dickov, who sustained a knee injury at Cardiff, was replaced in attack by Jonathan Stead.
For Palace, Michael Hughes, Andy Johnson and Mikele Leigertwood all passed late fitness tests and were fit to start while Gary Borrowdale came in for the rested Danny Granville.
Stead looked the likeliest player to open the scoring coming close with two headers early in the game. On 23 minutes a fairly innocuous looking free-kick played to the far post by Dominic Matteo turned out to be the perfect ball for Ryan Nelsen.
The New Zealander looked shocked to find himself unmarked inside the Palace area and was unfortunate to see his effort cannon against the upright and go out for a goal kick.
Moments later and with Palace still unnerved from Nelson's effort, Emerton jinked his was through the Palace defence only for his fierce shot to find the arms of goalkeeper Gabor Kiraly.
On the half hour Pedersen was brought down by Gonzalo Sorondo which resulted in the Uruguayan being booked and from the resulting free-kick Steven Reid fired narrowly wide from fully 25 yards.
This should have been a warning sign for Palace and they were made to pay shortly after.
On the stroke of half-time a free- kick from the left was viciously whipped in by Savage, leaving Pedersen free to pounce from inside the six-yard box and the Norwegian wasn't going to miss.
Pedersen timed his run to perfection and his left-footed toe-ender at full stretch found the underside of the bar on its way into the goal.
Palace's first effort of the match arrived ten minutes into the second half. Andy Johnson picked up the loose ball just inside the Rovers half and drove at the heart of the defence before unleashing a right-footed strike from 20 yards which was comfortably saved by Brad Friedel, low to his right.
Johnson was at it again moments later, capitalizing on some sloppy Rovers defending and forcing a smart save from the on-rushing Friedel.
Matteo came closest to doubling Rovers' lead on 66 minutes. Pedersen fired in a low cross from the left which the Rovers defender met stylishly on the volley, only for the ball to graze the sidenetting.
Minutes later and it should definitely have been two. Reid met Emerton's inviting cross, but the Republic of Ireland international put his free header wide of the post when he looked destined to score.
Reid and Stead had golden opportunities to seal the win in injury time, both finding themselves clean through on goal, but a nervous looking Rovers held on for the points.