كتب : Hatem Maher
Forward Mohamed Nagi 'Geddo' fired the hosts in front after 18 minutes but Abou-Greisha leveled the score eight minutes after the restart.
Ittihad's hopes of securing at least a draw were dealt a blow on 65 minutes when striker Mohamed Ragab was sent off.
The former Olympic man picked up a second yellow card for wasting time through dithering when substituted.
Abou-Greisha, who returned to Ismaili in January after an unsuccessful spell with Chinese side Zheijiang Lvcheng, notched the winner six minutes from time.
The Dervishes remained in the two-horse race for the league title as they aim to cause an upset and clinch their fourth domestic triumph in Egypt's premier competition.
Ismaili moved top on 54 points, two ahead of Ahli, who still have two games in hand due to their Champions League commitments.
Ittihad, who unlike the previous few seasons survived a battle against relegation, lie seventh in the 16-team table with 36 points.
Defensive Lapses
Ismaili's defensive lapses cost them in the early stages of the game.
Ragab almost broke the deadlock when he capitalized on a dreadful error by Mozambique defender Dario Khan to go clear on goal but he dragged his shot wide of the post.
Geddo made amends for Ragab's wasted opportunity to send the home fans into ecstasy.
He superbly nutmugged sweeper Abdul-Hamid Sami to go one-on-one with the keeper and notch home with aplomb.
Abou-Greisha, who played as a lone striker, restored parity in the 53rd minute when he chested Ahmed Samir Farag's left-wing cross and smashed home from inside the area.
Ismaili coach Ricardo Ferreira introduced strike duo Mostafa Karim and Nasigba John-Jumbo to support Abou-Greisha.
The substitutions bore fruit as the visitors took firm control of the game. They were also helped by the dismissal of Ragab.
Abou-Greisha scored the decisive goal with six minutes remaining via a close-range header to take his tally to four goals and give Ismaili all three points.