
Zambia scored early in both halves to deny underdogs Sudan a share of the spoils.
South African-based James Chamanga opened the scoring in the second minute with a well-taken shot from the edge of the area after having been set up by Jacob Mulenga.
Sudan, whose last appearance at the showpiece of international football dates back to 1976, were certainly not overwhelmed and could have grabbed an equalizer in the 11th minute when Badreldin El-Doud's powerful blast from outside the area slammed against the upright.
It was again Zambia who had the better start to the second half and scored their second goal five minutes after the restart, when Mulenga outjumped his marker after the ball hit the crossbar and headed home.
Just nine minutes later, the game was effectively over as Zambia made it three through Felix Katongo, who pounced on a ball that goalkeeper Mahjoub El Moez had only managed to palm away.
In the earlier game, defending champions Egypt got their title defence off to a fantastic start with an emphatic 4-2 victory against Cameroon in a Group C game.
The goals for the North Africans were scored by Mohamed Zidan and Hosni Abd Rabou, while Samuel Eto'o struck twice for the Indomitable Lions.
Egypt's first-half display was by far the best performance at this year's competition, and clinical finishing allowed them to go into the change rooms three goals up.
The Pharaohs opened the scoring in the 15th minute through Hosni, who converted from the spot after Andre Bikey was adjudged to have handled the ball.
After scoring, the Ismaili midfielder was ordered to retake his penalty, having hesitated in the run-up to the first attempt. He made no mistake the second time.
SC Hamburg player Zidan doubled his side's lead in the 17th minute after a brilliant one-two with Emad Moteab saw the Bundesliga player bearing down on Idriss Kameni before coolly slotting past the Cameroon goalkeeper.
Zidan's second goal in first-half injury time came out of nothing. Egyptian goalkeeper Essam al-Hadari played a speculative shot into the area, which Cameroon captain Rigobert Song headed to the feet of Zidan, who did well to control the ball before unleashing a powerful shot from outside the area.
Cameroonian coach Otto Pfister introduced three new players at half-time and was almost immediately rewarded for his bravery as Geremi was allowed to run down the flank before finding the head of Barcelona superstar Samuel Eto'o, who had no problems finishing.
Any possibility for Cameroon to threaten was killed off in the 82nd minute, when a long-range effort from Hosni gave Kameni no chance.
Eto'o pulled another back for Cameroon in injury time with a converted penalty after an Egyptian defender had fouled in the area.
Zidan said after the match that people should not be surprised that they managed to beat Cameroon.
"We are not only title defenders, we also came here to win the tournament," he said. "We have a very good side, and we can go far."
The Cup of Nations continues Wednesday in Ghana with two matches in Tamale, where South Africa take on Angola and Tunisia face Senegal in Group C.
By DB Peters, dpa