
It meant Algeria continued their winless streak at the finals since being crowned champions in 2019.
Baghdad Bounedjah put the Algerians ahead in the 19th minute with a well-taken goal but clumsy defending cost them when Nabil Bentaleb committed a foul and gave away a penalty, converted by Angola substitute Mabululu in the 68th minute.
Algeria have now failed to win in four matches at the Cup of Nations finals since lifting the trophy in Cairo.
They made a shocking attempt to retain the title at the last edition in Cameroon two years ago, going home early with one point from the group games and losing to tiny Equatorial Guinea.