It was a particularly sweet victory for manager Steve Bruce, who brought Gedo in on loan from Al Ahly when DJ Campbell pulled the plug on a move to the Tigers in favour of Blackburn.
Campbell started on the substitutes' bench but that did not save him from the Hull fans' ire.
Rovers had not lost in their last six and were coming off the back of a memorable FA Cup victory over Arsenal at the Emirates Stadium, however they were indebted to Jake Kean's magnificent one-handed save from David Meyler in the first half.
Gedo grabbed his third in as many games by side-footing home Stephen Quinn's cross and only another splendid save from Kean prevented that lead from being doubled.
But the Tigers made sure of the points when Elmohamady fired a first-time volley back past Kean just after the hour mark.
Hull dominated early on and came close to scoring when Quinn almost hooked the ball across to Gedo.
Robbie Brady then played a smart one-two with Quinn and lashed the ball across the face of the goal with nobody in a Hull shirt able to profit.
The visitors were getting dizzy chasing the Tigers' passing carousels but Bruce's men lost their rhythm when Colin Kazim-Richards embarked on a personal crusade to turn the game nasty.
His anger was sparked by a trip from behind by Alex Bruce and the forward earned a caution when he backed into Jack Hobbs, ensuring the centre-back came crashing back to the KC Stadium turf.
Hull soon got back to their familiar pattern, though, and almost scored through Meyler. The midfielder was all alone in the middle of the area and guided his header to Kean's right, yet the Blackburn keeper flung out an arm and somehow scooped the ball away.
He blocked the ensuing rebound from Gedo too and that prompted the travelling support to sing Kean's name, a tribute never afforded to former boss and namesake Steve.
With the game meandering towards half-time, Kazim-Richards elected to play with fire when he hacked down Meyler from behind and he was fortunate referee Tim Robinson showed leniency by only giving him a final warning.
Kazim-Richards returned for the second period but his side found themselves behind seven minutes after the restart.
Brady's corner came out to Quinn and he moved the ball on to his left before dinking a delicious cross into the middle, which Gedo simply had to side-foot back into the net.
An injury to Lee Williamson gave Campbell the chance to enter the fray, yet Kean was forced into another fine stop to deny Hobbs from a corner.
However, Hull did establish a two-goal lead in the 67th minute when Elmohamady joined his countryman on the scoresheet.
Brady bombed on down the left and turned back on to his right foot before arching a cross to the back post where Elmohamady had ghosted in undetected, and he smashed the ball home first-time to leave Kean helpless.
The icing on the cake for the home support came when goalkeeper David Stockdale shanked a clearance straight to Campbell, who miscontrolled under little pressure before firing out of play.
- Sports & Recreation
- Jake Kean
- Stephen Quinn