Nicky Forster, a player Trevor Francis discarded while he was boss at Birmingham came to Selhurst Park to haunt him with the only goal of the game for Reading.
Forster put away the visitors only clear cut chance of what was a match of few such opportunities and it took 18 minutes before either side had an attempt on goal with Julian Gray shooting at Royals keeper Marcus Hahnemann.
A couple of rash challenges from Matthew Upson and Tony Rougier resulted in cautions with the only other incident of note before Forster scored after 40 minutes.
He collected a header from Andy Hughes, outpaced Kit Symons on the right before firing past Alex Kolinko in the Palace goal from 15 yards.
Palace tried to up the pace after the break but really didn't have enough midfield invention to cause Reading many problems, Palace's best chance went to Tommy Black.
Put through by Andrew Johnson, he shot straight at the keeper from a narrow angle, Danny Granville fired into the sidenetting from a similar position late on, after SymonsÂ’ long ball dropped over Reading's defence.
The result lifted the visitors to fourth and this was their fifth clean sheet in a row in a run of eight wins in ten games.
Their manager, former Palace player, Alan Pardew said: “I love it here, it holds a special place in my heart. I was proud to bring my team here and win.”
Although he was disappointed with his team’s performance when in possession, Francis felt his players: “Had enough chances to claim a point but deserved no more, we were not able to impose ourselves.
“We were not creative enough in the middle and thus did not create enough chances.”