ABIDJAN, Ivory Coast: Ademola Lookman scored again to fire Nigeria into the semifinals of the Africa Cup of Nations with a 1-0 win over Angola on Friday.

Victor Osimhen failed to score after having a goal ruled out for offside but produced another tireless performance to help the Super Eagles emerge victorious from the tournament’s first quarterfinal. They did not concede for the fourth straight game.

Nigeria needed goalkeeper Stanley Nwabali — back after being stretchered off in the win over Cameroon — to deny Angola forward Mabululu an early lead.

But Nigeria went on to dominate the game in terms of possession and chances, and Lookman finally scored in the 41st minute after Moses Simon skipped a challenge and raced clear to set him up. It was Lookman’s third goal of the tournament after scoring both against Cameroon.

Nigeria captain William Troost-Ekong urged his teammates to concentrate after making a clearance to deny Estrela an immediate response.

“I’ve had some experience now that I think the most crucial minutes are always directly after kickoff and after goals scored or conceded,” Troost-Ekong told The Associated Press. “You just don’t want to fall in the trap of working so hard to finally get a goal and then giving something away. We’re learning, I think we’re getting better and better, more mature as well as a team.”

The Super Eagles maintained their dominance after the break, but Osimhen inadvertently impeded a good chance for Calvin Bassey and missed several late chances of his own.

The Napoli star thought he’d sealed the win with a header to Lookman’s free kick in the 75th, but the goal was ruled out for offside after a VAR review.

Nigeria reverted to a 5-4-1 formation with Osimhen alone up front as the Sable Antelopes probed for an equalizer.

Angola substitute Zini went closest when he hit the post.

Nigeria’s Frank Ogochukwu Onyeka was stretchered off late.

Both Nigeria and Angola danced their way into the stadium before the game on another hot and humid day in Abidjan. The temperature was 32 degrees (90 F) at kickoff.

Nigeria coach Jose Peseiro has made defense a priority. Nigeria never before won four straight games without conceding in the tournament.

“The formation helps us. The whole team is pulling their weight defensively,” Troost-Ekong told the AP. “It’s not just the defender or the goalkeeper. We’re working very hard to try and keep them away from our goal. And if you’re playing in a tournament, that has to be the basis of winning. How we are playing now, from the start, we believe we can win this tournament.”

LEOPARDS POUNCE FOR SEMIFINAL PLACE

Congo defeated Guinea 3-1 for the Leopards’ first win within normal time of the tournament in Friday’s other quarterfinal.

Congo captain Chancel Mbemba conceded a penalty in the 17th minute, from which Mohamed Bayo scored with Guinea’s first real chance in the 20th, but Mbemba atoned by equalizing from a difficult angle in the 27th.

A penalty from Yoane Wissa in the 65th and free kick from Arthur Masuakut that deceived the Guinea defense in the 82th ensured the Leopards reached the semifinals for the first time since 2015.

Congo, who won the last of their two titles in 1974, drew their three group games, then defeated Egypt on penalties to reach the quarterfinals.