Former Manchester United striker Manucho scored five minutes into each half for the Black Antelopes and Mohamed Bashir twice levelled for the Jediane Falcons at a sparsely populated Estadio Nuevo de Malabo.
The result opens the door for title co-favourites Côte d'Ivoire to reach the quarter-finals if they defeat neighbours Burkina Faso in the second half of a double-header.
Angola coach Jose Vidigal described the result as "fair." He added: "We keep our destiny in our own hands and maintain all our chances of qualifying. It was an interesting game. We led twice but unfortunately Sudan were able to level each time. It's normal Sudan took more risks as we'd already got our three points."
His opposite number, Mohamed Abdalla, commented: "We started by attacking because to continue in this competition we had to win. We let in the first goal on a major defensive blunder, the second on a penalty but my players aren't sufficently experienced. I'm happy that twice we were able to equalise. This game gives us huge motivation for our next one."
Angola came into the game anxious to silence critics like Burkina Faso coach Paulo Duarte, who accused his conquerors of being a route-one team fond of time wasting. Coach Mohamed Abdalla sprang a surprise by ditching long-time Sudan first-choice goalkeeper Almoiz Mahgoub and promoting Akram while fit-again Mohamed Tahir returned in the other change from a team narrowly beaten by the Ivorians.
Akram did not have a memorable introduction to Cup of Nations football as he picked the ball out of the net only five minutes into the game after an opportunist Manucho goal. Nagm Eldin reacted too slowly when dealing with a back pass and surrendered possession to the tall dread-locked Angolan, who burst through to score with a low shot across the goalkeeper and in off the far post.
A brass band played endlessly for a small crowd kept cool by overcast conditions at the 15,000-seat stadium, but there was little excitement on the pitch. The pace was slow with endless midfield duels and the game sprang to life only after 29 minutes when Sudan levelled as Bashir headed home a millimetre-perfect Mudathir Eltaib cross.
It was the first goal scored by the Falcons since 6 March 1976 when they drew 1-1 with Zaire - now the Democratic Republic of Congo - in a meaningless group game.
Manucho repeated his first half feat by scoring again five minutes into the second period, slotting a well-taken penalty into the left corner with Akram diving the right way but beaten by power and pace. There were a couple of significant mid-second half substitutions as the game meandered along with Sudan taking off captain Haitham Mostafa and former Germany youth international Nando Rafael coming on for Angola.
Sudan equalised a second time on 73 minutes when a misunderstanding between two Angolan defenders allowed Bashir to slam the ball past Carlos, who remonstrated furiously with his team-mates.