Mile Jedinak's first goal for Crystal Palace helped the Eagles extend their unbeaten run to six games with victory over Peterborough.
Jedinak took advantage of a fumble from Posh goalkeeper Paul Jones to fire home 14 minutes from time.
The goal was reward for an improved second half display after the visitors had dominated the first 45 minutes.
Home keeper Julian Speroni twice denied Posh to keep the game goalless and allow his team to snatch the late win.
Palace are now eight points behind the play-offs and still retain slim hopes of forcing their way into the end-of-season reckoning.
Peterborough stay 18th, 10 points clear of the relegation zone.
The visitors started the game well and Tyrone Barnett's strike from just outside the area forced Speroni to tip over, before the Palace goalkeeper again magnificently thwarted Barnett after the striker had cut through the defence.
Palace did start to get to grips with their challenge and Darren Ambrose was inches from giving them the lead when his effort from Jermaine Easter's lay-off was deflected onto the upright by Gabriel Zakuani.
Both teams had further chances to break the deadlock with Patrick McCarthy heading wide from Ambrose's free-kick for Palace and Tommy Rowe going close with an effort from 20 yards for the visitors.
The deadlock was finally broken in the 76th minute when Posh goalkeeper Paul Jones fumbled Ambrose's free-kick to the feet of Jedinak, who swivelled and fired into the net.
Peterborough battled to get back on level terms but the home side held on comfortably.
Crystal Palace boss Dougie Freedman: "Pressures come in different ways and in the past we have had to play a more defensive game because of the situation we were in.
"Things have changed now because we have to try and open up teams a bit more, but there is a real feelgood factor around the place so now it's up to me to decide when we need to take a few more chances going forward."
Peterborough manager Darren Ferguson: "What disappointed me was that we lost our composure. We knew that Palace like shooting towards their fans so I told the players at half-time to make sure they get hold of the ball and pass it around.
"In the end they didn't do that so that's disappointing. Today was an opportunity to get the right result but it's still in our hands. Now we need four wins from 13 games and we will be safe."