Blues suffered their first away defeat of 2013 with a heavy loss at the KC Stadium.
A brace each from George Boyd and Gedo, as well as a solo strike from Robert Koren, did the damage for Hull City, while Peter Lovenkrands and Chris Burke struck back with late consolations.
The visitors were in buoyant mood heading into the game with just one defeat in their last eight games and no loss in their previous five away fixtures.
However Blues were brought crashing down to earth after just 49 seconds when Boyd, making his home debut, beat the offside trap to latch on to Robbie Brady's throughball and fire Hull into an early lead.
That set the tone for The Tigers who, eager to hit back from their own heavy defeat at Bolton Wanderers last weekend, were in a ruthless mood.
Blues were two down less than ten minutes later. Egypt striker Gedo latched on to a hopeful punt forward, raced past skipper Steven Caldwell, who was later withdrawn through illness, and coolly slotted past Jack Butland from close range.
Despite the regular setbacks, Lee Clark's side did continue to plug away but found themselves up against a sturdy Tigers backline and David Stockdale in fine fettle. Mitch Hancox carved open the first half-chance for Blues in the 16th minute when he played in Lovenkrands for a shot from the left side of the area that sailed wide.
At the other end, Ahmed Elmohamady tried his luck from distance with a rasping drive that had Butland at full stretch but bounced off target. Butland was again called into action in the 20th minute to produce a fine double save to deny Gedo and Boyd from close range.
However, with 33 minutes on the clock, it was 3-0 to Hull and Boyd further enhanced his reputation with the KC faithful with his second. A well worked move from the right wasn't dealt with and Boyd fire a low effort into the bottom corner off the fingertips of Butland.
Burke had Blues' best chance of the first-half in the 39th minute. Nikola Zigic's fine throughball played in the Scotland international but his heavy touch fell kindly for the outrushing Stockdale.
If Blues thought they had a mountain to climb in the second half it was made even steeper five minutes into the second-half. Tigers skipper Koren firing a 25-yard drive in off the diving Butland.
There was no stopping Hull but thankfully Butland was on hand in the 52nd minute to brilliantly tip over Gedo's close range header.
However Gedo wasn't to be denied in the 76th minute and he joined Boyd with a brace of his own. Compatriot Elmohamady picked out Gedo six yards out and he sent home his header off the body of Butland.
Despite the scoreline, Blues do deserve credit for the way they continued to plug away right up until the final whistle. That determination was rewarded with two goals for the visitors in the 83rd and 87th minute.
Lovenkrands saw his deflected shot from 25 yards loop over Stockdale for 5-1 before his former Rangers colleague Burke picked up Zigic's lay off to fire home a low shot four minutes later.