Portsmouth's relegation fight continued after a narrow victory at Fratton Park as a goal in each half gave the home side all three points in a tense encounter for their supporters.
As the games began to run out for the Fratton Park faithful they knew that nothing less than a win would be good enough to keep alive their chances of avoiding the drop.
It was Palace though who had the best chances of the opening period with Wilfried Zaha having a couple of early opportunities. One effort flew over the bar and another that had to be saved by Jamie Ashdown.
Antonio Pedroza had the best chance to break the deadlock in the early exchanges but as the ball from Chris Martin came across field in front of goal the young Mexican put the ball over both Ashdown and the bar before Pompey began to create chances of their own.
First Dave Kitson headed over the bar and then Luke Varney saw an effort hit the post but it was not long before the deadlock was broken.
Scott Allan's 30 yard shot took a major deflection off Nathaniel Clyne and with Julian Speroni wrong footed he had no chance as the relegation fighters received a large slice of luck.
On-loan forward Chris Maguire almost increased the lead just before the interval but his drive towards goal went just wide of the target and Palace went in 1-0 down.
In the early stages of the second half, Pedroza saw a close-range effort pushed away by Ashdown before another deflection helped Portsmouth increase the lead.
Allan's corner fell to Greg Halford at the back post and the full-back's header towards goal was deflected into the net to give the home side a two goal cushion.
Dougie Freedman introduced Darren Ambrose and it wasn't long before the midfielder set about getting Palace back into the match. Luke Varney was adjudged to have fouled Zaha in the box and the Eagles' leading scorer stepped up to fire the spot-kick past Ashdown.
Ambrose then nearly got his side on level terms with a shot from distance from a free kick but it flew inches wide of the target as the visitors pushed for something from the game.
Moments later they thought they had but a Paddy McCarthy effort was ruled out for a foul on Ashdown before, at the other end in the closing minutes, Paul McShane made a brilliant clearance off the line to deny Chris Maguire as the home fans thought they had ended the night with a third.
Portsmouth Ashdown, Ward, Rocha, Pearce, Rekik, Allan (Harris 85), Halford, Norris, Maguire, Kitson, Varney.
Subs Not Used: Mokoena, Futacs, Scapuzzi, Magri.
Crystal Palace Speroni, Clyne, McCarthy, McShane, Moxey, Garvan, Pedroza (Scannell 77), O'Keefe, Zaha, Martin (Appiah 57), Parr (Ambrose 64).
Subs Not Used: Price, De Silva.
Att: 14, 847 Referee: Simon Hooper (Wiltshire).