The first leg result in Garoua hands the advantage to the Egyptian club, who will host the return on Oct.20.
But their coach Mohamed Youssef will be banished to the stands after being sent off for dissent. He was red carded midway through the second half.
Coton Sport forward Ewangue Mbongo cut inside the Ahli defence before striking home a low shot to the near post to hand the hosts a 1-0 lead after 33 minutes.
Within a minute Coton Sport were forced to clear off the line to deny Ahmed Abdulzaher's header before Aboutrika's silky skills conjoured up the equaliser in stoppage time at the end of the first half.
Ahli might have snuck the win had Al-Sayed Hamdi not missed a good chance just four minutes from the end.
The two teams returned 24 hours after a torrential storm saw their game abandoned just short of the hour mark on Saturday, with the pitch badly waterlogged but it evaporated sufficiently by kick off time on Sunday to allow the match to take place.
The winner of the tie meets either Esperance of Tunisia or South Africa's Orlando Pirates. They played out a goalless draw in their semi-final, first leg tie in Soweto on Saturday.