Congolese striker Kebanu scored the RD Congo goal in the 64th minute following a low shot that left goalkeeper Hugo Marques 'nailed'.
With the result of this game, of the fourth round of group D, Angola remains in the last position with only one point and with remote chances of qualification, while DR Congo occupies the third position with six points.
After an apathetic first half for the 'Palancas Negras', who only settled their game after 15 minutes, the balance dominated for several moments the match, which took place at the 11 de Novembro Stadium, in Luanda, with the most offensive Congolese.
In the second part, Angola came under pressure on the opponent, tried to target the goal of Kiassungua, but, in a distraction from his defense, Kenabu scored.
The 'Palancas Negras' still reacted, Pedro Gonçalves made some changes, but the 'Leopards', as the RD Congo team is known, lowered their lines, played in the contention and kept the advantage until the final whistle of the Luso-South referee African, Victor Gomes.
At the end of the game, Angola's coach, Pedro Gonçalves, admitted that with this defeat, the Angolan team "is mathematically out of the CAN", showing, however, "satisfied" by the performance of its players during the game.
"And, in fact, we created our situations, it was a very shared game, I am very satisfied with the performance of my players and I feel that the result was not done justice," he told reporters.
For his part, the coach of the Congolese national team, Cristian Nsengue, valued the challenge, considering that Angola "is an excellent team, very disciplined", but noted: "We came to win, we managed and I believe in the qualification for CAN."
The group is led by Gabon and Gambia, both with seven points, playing the fifth round in March 2021.
The 33rd edition of CAN was scheduled for next year, but was eventually postponed to 2022 - despite maintaining the CAN2021 designation - to not coincide with the Copa America and Euro2020, which were postponed due to the covid-19 pandemic. .