كتب : Hatem Maher
Mahmoud Selim's "Shiko" penalty two minutes past the hour mark for Olympic cancelled out Sayed Mowaad's opener just before the break.
Mohamed Soliman "Hommos" put Ismaili ahead in the 67th minute before defender Moatassem Salem ensured the win one minute before the final whistle.
The result maintains Ismaili's position on top of the league table with 16 points; while Olympic lie second from bottom on just two points.
Dervishes will host Cairo giants Zamalek in their next league game.