Ivory Coast had to settle for a point in their opening African Nations Cup Group D match after they drew 1-1 with Guinea and finished the game with 10 men.
Mohamed Yattara stunned Ivory Coast, who are ranked Africa's third-best side behind Algeria and Tunisia, with his 36th-minute volley before the favourites saw striker Gervinho sent off for hitting Naby Keita in the face.
Second-half substitute Seydou Doumbia gave the subdued crowd something to cheer about with his 72nd-minute equaliser, but with a man down, Ivory Coast were unable to go on and claim the win.
"We bounced back. It's a good point for us,'' said Yaya Toure.
Volker Finke's new-look Cameroon side needed a late equaliser to escape with a 1-1 draw from their opener against Mali.
Mali led through Sambou Yatabare's 71st-minute goal but New York Red Bulls full-back Ambroise Oyongo hit back for the Indomitable Lions.
Yatabare thought he had won it in stoppage time but his header was correctly disallowed for offside.