Nathan Delfouneso gave the visitors a lead their first-half dominance fully merited but Seasiders boss Michael Appleton was left to rue chances passed up by Wes Thomas and Thomas Ince.
Owen Garvan rounded off a clinical Palace counter-attack to level matters early in the second period and, after the same player tested the crossbar, Glenn Murray headed his 18th goal of the season.
That seemed enough to close Palace to within a point of npower Championship leaders Cardiff until Dicko - a man Holloway christened as a "super sub" earlier this season - converted Wes Thomas' drilled cross.
Fellow substitutes Kevin Phillips and Ludo Sylvestre went close as Blackpool finished the stronger but had to settle for a fifth draw in six unbeaten games under Appleton.
Seemingly intent on proving a point to their former boss, Blackpool flew out of the blocks and fashioned three openings inside the first four minutes with Craig Cathcart, Isaiah Osbourne and on-loan Bournemouth striker Thomas all going close
Palace's defence proceeded to repel a steady diet of corners as Blackpool dominated possession, but the hosts threatened to take an undeserved lead in the 25th minute when Garvan launched a swift counter-attack, and Wilfried Zaha drew a sharp stop from Matt Gilks.
Mile Jedinak struck a pass against Eagles team-mate Damien Delaney to leave Thomas through on goal, but he sliced wastefully high and wide.
His blushes were spared in the 37th minute when Pool defender Alex Baptiste broke up a Palace attack and released Ince to cut inside and whip a vicious ball across the six-yard box, where Delfouneso stole in at the back post to nod home.
Thomas could not repeat the trick when Delfouneso turned provider and there was still time before the interval for Ince to latch on to a Tiago Gomes flick and blaze over.
They were misses Blackpool would live to regret as Palace levelled seven minutes into the second period. Yannick Bolasie collected Zaha's overhit cross, and when he sent the ball back into the box from the left, Garvan was on hand to head past Gilks.
A minute later Garvan was inches away from a second, rattling the crossbar from a 25-yard free-kick after Delfouneso felled Zaha, but Palace completed the turnaround in the 64th minute.
Garvan collected Zaha's pass to clip a cross to the far post. Murray was left with plenty to do, moving away from goal, but executed his header back across Gilks to perfection.
Dicko lashed an earlier opportunity narrowly wide before sparking jubilant celebrations among the travelling support by applying the finishing touch when Thomas drove the Palace defence backwards.