Kevin Phillips was the Palace hero with a hat-trick on his first start for the club as Ian Holloway's side climbed to within two points of the automatic promotion places after comfortably seeing off Hull.
The promotion chasing rivals were at each other from the off with George Boyd close to latching onto a through-ball and Peter Ramage seeing an effort cleared off the line after David Stockdale dropped Jacob Butterfield's cross inside the first five minutes.
Hull had come out of the blocks quickly with Ahmed Elmohamady causing the Eagles problems down their left but a number of corners came to nothing and then Palace began to dictate with Jonny Williams to the fore.
The little midfielder soon won a penalty after a one-two with Dean Moxey ended when he was felled in the box and only a fantastic save from Stockdale prevented Glenn Murray adding to his tally for the season from the spot. Elmohamady then should've given the visitors the lead but volleyed a corner over when well placed before the game became Williams' again. The Welshman beat three men in midfield and played in Murray and when the forward's shot hit an arm the referee pointed to the spot.
Hull probably felt hard done-by by the decision and would've been cursing their luck again moments later when Stockdale got a hand to Phillips' penalty only to see the ball ricochet over the line. That was the enough to give Palace the lead at the interval and better was soon to come.
Both sides upped the energy after the break but it was Palace who made the most of their start as Wilfried Zaha broke down the right and his square ball was tucked home by Phillips to put breathing space between the two teams. Less than two minutes later it was 3-0 as another Zaha pass inside found Phillips who this time had more work to do but curled his shot into Stockdale's corner, via a slight deflection, to secure his hat-trick.
An excellent Palace performance it was but 3-0 seemed harsh on Hull and the introduction of Jay Simpson sparked the visitors into life again. Elmohamady's cross from the right looked fairly innocuous but Simpson leapt and twisted to send a looping header into Julian Speroni's top corner to give the Tigers some hope.
That only lasted two minutes though as Zaha, who had been fantastic in the second half, played a neat one-two with Murray and raced through to tuck his finish home and secure the points for the Eagles. There was still time for David Meyler to send a few jitters round Selhurst as he headed home Robbie Brady's inswinging free-kick to make it 4-2. That was virtually the last action of the game though as Ian Holloway's side made it four wins in a row at Selhurst after another excellent display.
Palace: Speroni; Dikgacoi, Ramage, Delaney, Moxey; Jedinak, Butterfield (Dobbie 78); Zaha, Phillips (Bolasie 74), Williams (Parr 65); Murray
Subs Not Used: Price, Marrow, Wilbraham, Moritz
Hull: Stockdale, Chester (McShane 59), Hobbs, Koren (Simpson 69), Gedo, Elmohamady, Bruce, Quinn (Fahti 69), Brady, Meyler, Boyd
Subs Not Used: Jakupovic, Evans, Faye, Proschwitz