The Indomitable Lions suffered their second defeat of the tournament after losing to Congo by the same margin in the opening game of the group, and sends them crashing out of the tournament.
However, it was Angola who had the first sight of goal. Paty managed to find space just midway through the Cameroon half before lining up a fierce shot which Cameroon keeper Jean Oscar Kalati parried away on 18 minutes.
Cameroon replied with an attack of their own three minutes later, winger Patrick Moukoko cutting in from the left to set up Junior Bitang who could not keep his effort on target.
Angola opened the Cameroon defence and won a penalty on 28 minutes after a clumsy challenge by Bertrand Owundi on Vladimir Va for a penalty and captain Ricardo Job hammered home what turned out to be the only goal of the match.
The Indomitable Lions continued to mount pressure on the Angola defence who were composed and strong.
Cameroon keeper Kalati pulled one the best saves of the tournament on 52 minutes diving to his right to deny Herenilson's pinpoint header inside the six yard area.
Minutes later, midfielder Willy Namedji saw his clever turn shot inside the area blocked when it was destined for the Angola net. Defender Alphonse Tientcheu also smashed a lose ball outside the box on target but was denied by Landu Mavanga.
Va missed a good opportunity to extend Angola's lead three minutes from time tapping Augusto Quibeto's cross off target.
The win places Angola at the top of Group D with 4 points one more than Congo who play Burkina Faso later.
Total Man of the Match: Vladimir Felix (Angola)
Srdan Vasiljevic (Head Coach, Angola)
I am happy that my team for managing to beat Cameroon, a big name in African football. It was not easy for us because we had a very strong opponent in front of us. The players applied the instructions to the letter. Now, we have to think about our last game against Congo.
Rigobert Song (Head Coach, Cameroon)
We made some mistakes during the match and that's normal because the players are still learning. I am happy with the performance of the players who have given their maximum. I will continue to work with them to make progress. On the other hand, I am disappointed by the cruel end. We're eliminated from the tournament and it's a huge disappointment.