Goals early in each half proved decisive for Zambia as they moved to the top of Group C with a comfortable win over Sudan in Kumasi.
Mulenga put Zambia 2-0 up early in the second half
A well-struck shot by James Chamanga put Zambia ahead after three minutes before Sudan wasted several good first-half chances to equalise.
Jacob Mulenga headed in Zambia's second goal early in the second half after Clive Hachilensa hit the crossbar.
Felix Katongo wrapped up the victory from close range just before the hour.
Sudan had waited 32 years to play at the Nations Cup, but their hopes of starting with a win were dented when Zambia scored the fastest goal of the tournament so far.
Chamanga played a one-two with Jacob Mulenga outside the box, before powering the ball into the far corner.
The early disappointment failed to dampen Sudan's spirits, and they almost equalised after 12 minutes.
A fierce half-volley by Badreldin El Doud from the edge of the penalty area hit the inside of the post with Zambia goalkeeper Kennedy Mweene well beaten - and the Nile Crocodiles had the upper hand for the rest of the first half.
Their defence was solid, captain Haitham Mustapha dominated the midfield and giant 37-year-old striker Faisal Agab troubled the Chipolopolo back line.
On the half-hour Sudan Alaeldin Ahmed Gibril blazed the ball over the bar with Mweene off his line and the goal gaping.
Sudan paid for their missed opportunities when Zambia scored the game's decisive second goal.
A powerful header by Clive Hachilensa hit the crossbar, and Mulenga nodded the rebound down into the goal.
The game slipped beyond Sudan's reach on 59 minutes when Mahjoub El Moez failed to hold on to Rainford Kalaba's shot and Felix Katongo pushed home from close range.
Mulenga nearly scored his second with six minutes remaining, but was denied by an acrobatic save by El Moez.
Although the match was between two of the tournament's smaller teams, a sizeable crowd watched the game at the Baba Yara Stadium in the Northern city of Kumasi.
It was in stark contrast to Monday's Group A match between Morocco and Namibia in Accra, which was played in a near-empty stadium.
Sudan: Elmuiz Abdalla, Bakhit, Ali Elkhidir, Eldin Ahmed Gibril, Lado, Karar, El Bashir (Ali Idris Farah 80), Bader Eldin Abdalla, Ahmed (Yousif Hado 24), Kamal Tambal, Agab Sido (Babiker 57).
Subs Not Used: El Basha Adam, El Hadi Salem, El Tayeb, Hameed Amari, Hassan Ali, Hassan, Kuku, Mohamed Abdalla, Tahir Osman.
Booked: Bakhit, Bader Eldin Abdalla.
Zambia: Mweene, Nketani, Musonda, Mwanza, Hachilensa, Bakala, Kalaba, Felix Katongo, Jacob Mulenga, Phiri (Mayuka 70), Chamanga (Clifford Mulenga 83).
Subs Not Used: Chinyama, Himonde, Kakonje, Kampamba, Kasonde, Njovu, Poto, Sunzu.
Booked: Mwanza, Felix Katongo.
Goals: Chamanga 2, Jacob Mulenga 51, Felix Katongo 60.
Ref: Badara Diatta (Senegal).