Substitute Mohamadou Idrissou headed the 86th-minute winner to complete a late scoring flurry in which Cameroon struck twice within five minutes to snatch the lead only for Zambia to level from a penalty.
Geremi and Samuel Eto’o were the other marksmen for the winners while Jacob Mulenga gave Zambia an early lead and captain Christopher Katongo levelled from a spotkick with nine minutes left.
Gabon, who fought out a dour goalless draw with Tunisia in the first half of a double header, lead the pool with four points. Cameroon have three, Tunisia two and Zambia one ahead of the final mini-league fixtures next Thursday.
“We can become better, but we started from a low base,” commented coach Paul Le Guen, who took over Cameroon when they were last in their World Cup/Africa Cup of Nations qualifying group.
The former Lyon, Paris Saint-Germain and Rangers boss added: “We found ourselves in difficulty here because Zambia play really well. The first half was very tough for us. Afterwards things got better but I know they’re good and that we were fortunate to win and to take the three points.”
The Frenchman made two changes from the team shocked 1-0 by Gabon in their opening match, with midfielder Stephane Mbia and striker Tchoyi Somen replacing Landry Nguemo and Achille Webo.
Zambia, also coached by a Frenchman in Herve Renard, stuck with the side that led Tunisia before having to settle for a 1-1 draw in a match they could easily have won.
The Chipolopolo (Copper Bullets) needed no incentive to beat the Indomitable Lions, having suffered a humiliating 5-1 defeat against them at the same stage of the last Nations Cup in Ghana two years ago.
Renard had warned his squad that there is nothing more dangerous than a wounded lion and they heeded his advice by snapping at the feet of their more illustrious opponents from the kick-off.
The in-your-face approach of a country trying to reach the second round for the first time since 1996 paid off after only eight minutes when Netherlands-based Mulenga struck.
This goal once again exposed Cameroon as a team prone to slapstick defending, with a careless Geremi pass intercepted by Felix Katongo, who burst past the veteran defender and crossed from the left.
Rigobert Song, another long-serving defender who was held responsible for the Gabon goal, headed the ball against his goalkeeper Carlos Kameni as he attempted to avert danger and the rebound fell to Mulenga who tapped it home.
Cameroon boasted an attack starring three-time African Footballer of the Year Eto’o, but Zambia goalkeeper Kennedy Mweene was not tested until the 36th minute when he reacted swiftly to push away a Jean Makoun drive.
A double save from Kameni soon after saved Cameroon from falling further behind as he parried a Rainford Kalaba free-kick and got up quickly to foil Katongo, who reached the rebound first.
The second-half goal deluge began on 68 minutes when an innocuous Geremi cross from the touchline crept under the body of Mweene into the far corner before Eto’o blocked a clearance to fire his team in front four minutes later.
Katongo equalised when Mulenga was sent flying by Kameni only for Idrissou to soar above Stoppila Sunzu and head wide of Mweene to give Cameroon their third triumph over Zambia in four Nations Cup clashes. (SW/MG/rex)