Second-half goals from David Nugent and Kelvin Wilson eased Preston into the fifth round of the FA Cup.
Nugent set North End on their way to victory
Nugent put North End 1-0 up seconds after the restart, shooting home from 12 yards after a superb run.
And Wilson settled the tie with a close-range tap in after keeper Scott Flinders missed a Lewis Neal corner.
Carl Fletcher hit the post for Crystal Palace while keeper Andy Lonergan made a fine first-half double save to deny James Scowcroft and Clinton Morrison.
Eagles skipper Fletcher had already seen a header go narrowly over the bar when Lonergan pulled off a sharp save from Scowcroft's deflected shot and then the keeper blocked Morrison's goalbound shot.
The visitors rarerly threatened before the break, although Michael Ricketts saw a fine 18-yard shot go inches wide with Flinders beaten.
606 DEBATE: Your views on Preston's victory
But Preston took the lead seconds after the interval and they never looked back.
Nugent embarked on an eye-catching 40-yard run and, after making the most of a fortunate ricochet, smashed the ball home from an acute angle.
Paul Simpson's Championship high-flyers then started to play on the break and Palace struggled to create much in front of goal.
Lonergan was forced into action to keep out a fierce Fletcher effort.
But the visitors secured their spot in the fifth round when Flinders flapped at Neal's corner and Wilson gleefully side-footed the ball into the net from close range.
And Preston could have added a third in injury-time when substitute Neil Mellor shot wide with the goal at his mercy.
Crystal Palace manager Peter Taylor on abuse from fans:
"I wasn't very impressed by that, to be honest.
"Here, if you win you get clapped off and if you lose you get booed - there's no in between at all.
"As a manager, I always work and try as hard as I can. I saw quite a few of the Preston players coming off at the end, watching our fans and looking a bit stunned. It's hard to take but we have to get over it."
Preston manager Paul Simpson on David Nugent:
"We're delighted to have him but I haven't been under lots of pressure to sell and that's all credit to the chairman.
"We've now only got a few days to hang on for but if the chairman stays strong, he won't be leaving. "David also deserves to be applauded because he hasn't ever been distracted by all the speculation.
"It's all very easy in the modern age for footballers to tell the world that they want to leave and play at a higher level but he hasn't done that. He has totally focused on doing his job."
Crystal Palace: Flinders, Lawrence, Ward, Hudson, Butterfield (Freedman 68), McAnuff, Fletcher, Green (Ifill 56), Kennedy, Scowcroft (Kuqi 67), Morrison.
Subs Not Used: Speroni, Cort.
Preston: Lonergan, Alexander, Wilson, Chilvers, Hill, Sedgwick (Whaley 71), Pugh, McKenna, Lewis Neal, Ricketts (Ormerod 79), Nugent (Mellor 87).
Subs Not Used: Nash, St. Ledger.
Goals: Nugent 46, Wilson 83.
Ref: L Probert (Gloucestershire).