Cameroon's African Nations Championship hopes were ended after two matches on Saturday as Ricardo Job Estevao's first half penalty took Angola past them in a 1-0 victory.
Elimination at this stage represents the first time Cameroon have fallen in the group stage of the CHAN.
Job stepped up to convert from the spot on the half-hour mark after Bertrand Owundi pushed over an opponent in the box, with Cameroon coach Rigobert Song contesting the award of the penalty after the match.
Angola's win keeps them in top spot in the group on four points, although depending on the result in the day's later kick off between Burkina Faso and Congo-Brazzaville, they may still need a win against the latter in their final group game to progress.
Cameroon's campaign ends after two matches, with the Indomitable Lions beaten by a late Junior Makiesse spot kick vs. Congo in their opener, and again paying the penalty here.
Song's Lions were much improved after their opening defeat, but for all of their possession and buzzing movement, they struggled to forge out many clearcut chances, although Willy Namedji and Clarence Bitang did have efforts in the first 20 minutes.
Cameroon thought they should have a penalty of their own just before the break but their appeals fell on deaf ears, while Frantz Pangop missed arguably the brightest opening of the second period when he failed to finish off a fine team move in the 63rd minute.
After the break, it was Angola who went closest when midfielder Herenilson's close-range header was blocked by Oscar Gwot in the 51st minute, and as in the first game, Cameroon were left to regret an inability to forge clearcut chances when in need of an opening.
Cameroon face Burkina Faso in Tanger in their final group match, while Angola and Congo clash in Agadir.