Mohamed Soliman "Hommos" goal, seconds before the break, cancelled Hossam Ashour 21st minute's lead to keep both sides in challenge for this season title.
Ismaili started to work their magic since the first second against a quiet and weakened Ahli side.
They could have opened the scoring early as left winger Sayed Moawad cut in the area but his shot was deflected to a corner by keeper Essam Al-Hadari.
Ahli scored against the run of play when Ashour got a deflected pass from Mohamed Abou-Treika in the area and dribbled past the keeper to score in the empty net.
Eight minutes later, Hosni Abd-Rabou sent a well-placed free kick bouncing back from the woodwork.
Mostafa Karim was also sent clear on goal but his attempt was denied by the Al-Hadari, who had to make some heroic saves during the game.
The Iraqi striker got through managed to score two minutes later but the offside flag was up and the goal was cancelled.
The fans berupted into celebrations when Homos connected with Omar Gamal's low cross after magnificently getting rid of a couple of Reds' defenders.
Ahli manager Manuel Jose went into the second-half with more offensive options as he brought in striker Flavio instead of right winger Ahmed Adel who was totally overshadowed by Moawad.
He could have snatched the winner but his powerful header, on Emad Meteb's cross, was rejected by the left post.
The match was then suspended for 15 minutes because of electricity troubles, which almost killed the game as both sides seemed happy with the result and the point.
The result leaves Ahli in the third place with 18 points while Ismaili are fourth with 13 points.