Ivory Coast made a winning start in Group E after defeating Equatorial Guinea 1-0 at the Stade Omnisport de Douala.
Ajax Amsterdam striker Sebastian Haller started in the attack for the Elephants alongside Max Gradel and Maxwell Cornet.
Guinea, meanwhile, were able to call on Emilio Nsue and Dorian Hanza in the attack.
However, one was all it took for the 2015 champions to get the job done as Gradel rifled the ball into the top corner from edge of the box in the fifth minute.
Mali started their Group F campaign on a winning note after edging Tunisia 1-0 in a chaotic match at Limbe Stadium.
After an eventful first stanza, Ibrahima Kone finally broke the deadlock for Les Aigles three minutes into the second stanza from the penalty spot after a handball by Ellyes Skhiri in the box.
Tunisia were given a lifeline in the last 13 minutes after they were awarded a penalty from a Video Assistant Referee (VAR) review, following a handball by Djenepo but Khazri could not level matters as his spot-kick was saved by goalkeeper Bosso Mounkoro.
There was confusion towards the end of the game as the referee blew his whistle indicating full-time but there was still five minutes left on the clock and the game resumed briefly, before wMali reduced to ten men after El Bilal was sent off.
Tunisia were protesting in the tail end after the referee blew his final whistle in the 89th minute, without additional minutes.
Debutants Gambia made their own history after clinching victory at their first attempt by edging Mauritania 1-0 in Group F at Limbe Stadium.
The Lions of Chinguetti's attack were led by former Fulham striker Aboubakar Kamara alongside France-based forward Pape Ibnou Ba while the Scorpions boasted the attacking duo of Bologna forward Musa Barrow and Switzerland-based Assan Ceesay.
Gambia had a dream start after Ablie Jallow gave them the lead in the tenth minute with a smashing strike from the edge of the box after he was setup by Barrow.
Mauritania came close to equalising nine minutes before the half-time break after a header by Ibnou Ba produced a stunning save from goalkeeper Madou Jobe.
However, Didier Gomes Da Rosa's charges could not get shots on target in the second stanza, as Gambia held on for their first win in the tournament's history.
Mauritania will be up against the wounded Tunisia in their next group encounter on Sunday while Gambia will face off against Mali.
