ABIDJAN - A solitary Ademola Lookman goal was enough for Nigeria to beat Angola on Friday and qualify for the Africa Cup of Nations semi-finals, while the Democratic Republic of Congo joined them by coming from behind to defeat Guinea.
Atalanta forward Lookman, the former England Under-21 international, had scored both goals in Nigeria's defeat of Cameroon in the last 16 and he made it three in two games as the Super Eagles claimed their third 1-0 victory of the tournament.
The goal came four minutes before half-time at the Felix Houphouet Boigny Stadium, with Moses Simon collecting a pass on the left, accelerating away from Kialonda Gaspar and driving into the area before cutting the ball back for Lookman to finish.
That was enough for Nigeria to win through to their 15th Cup of Nations semi-final, which is more appearances than any other country.
Nigeria have now kept four consecutive clean sheets, validating coach Jose Peseiro's approach which has been based around making sure they do not concede goals first and foremost.
Nigeria advance to a last-four tie next Wednesday against Cape Verde or South Africa in the central Ivorian city of Bouake -- those sides meet in the quarter-finals on Saturday.
Friday's second match saw DR Congo see off Guinea 3-1 across Abidjan at the Ebimpe Olympic Stadium.
Guinea had reached the last eight after winning a Cup of Nations knockout tie for the first time, and they went in front midway through the first half.
DR Congo then clinched their place in a first semi-final since 2015 thanks to a stunning late free-kick by Besiktas full-back Arthur Masuaku from way out on the left flank.
They had qualified for the knockout phase despite drawing all three matches, and then overcame Egypt on penalties in the last 16.
DR Congo now stay in Abidjan for a semi-final against either Mali or hosts Ivory Coast, who meet in the last eight on Saturday.