Defender Chaker Alhadhur started in goal for Comoros who were without their recognised goalkeepers for the last 16 match at the Stade Olembe in Yaoundé.
The debutants had a difficult start against Cameroon when captain Nadjim Abdou was sent off after 7 minutes for a foul on Moumi Ngamaleu.
With a man down Comoros put up brave performance against the Indomitable Lions. Andre Onana had to be at his best to keep Cameroon in the match, the Ajax goalkeeper pulled the first save of the match inside two minutes.
Onana parried away Youssouf M’Changama free kick before Collins Fai cleared the rebound.