Equatorial Guinea s defender Carlos Akapo (L) fights for the ball with Senegal s forward Sadio Mane during the Africa Cup of Nations (CAN) 2021 quarter-final football match between Senegal and Equatorial Guinea at Stade Ahmadou Ahidjo in Yaounde on January 30, 2022. AFP
Mane set up the opener for Famara Diedhiou in the last-eight encounter but Equatorial Guinea fought back to equalise through Jannick Buyla early in the second half.
Substitutes Cheikhou Kouyate and Ismaila Sarr then both found the net to seal Senegal's place in the semis and a meeting with Burkina Faso on Wednesday at the same Ahmadou Ahidjo Stadium in the Cameroonian capital.
Africa's top-ranked side remain on course to win their elusive first Cup of Nations title, three years after losing to Algeria in the final in Egypt.
Mane was given the all-clear to play after suffering suspected concussion in a nasty collision during Senegal's 2-0 win over Cape Verde in the last round.
The 29-year-old crossed paths with his Liverpool team-mate Mohamed Salah as he entered the stadium, where Egypt had beaten Morocco in their quarter-final a little earlier.
Now Mane joins Salah in staying on until the last weekend of the tournament. They could meet in the final, with the Egyptians facing Cameroon in the other last-four tie on Thursday.
Backed by the majority of the crowd, the Lions of Teranga went in front just before the half-hour mark when Mane set up Diedhiou to score.
Equatorial Guinea, who had ousted Mali on penalties in the last round, thought they had a penalty shortly after half-time for a Kalidou Koulibaly handball, but the South African referee overturned the decision after reviewing the images.
They did equalise in the 57th minute when Buyla, one of a host of Spanish-born and based players in the squad, toe-poked into the corner.
Senegal coach Aliou Cisse turned to his bench and Crystal Palace midfielder Kouyate made a quick impact, pouncing for an easy finish after a horrible mix-up between Saul Coco and Carlos Akapo when Equatorial Guinea failed to clear a corner.
Also on from the bench, Sarr then made sure of the victory following superb play down the left by Saliou Ciss.
(For more sports news and updates, follow Ahram Online Sports on Twitter at @AO_Sports and on Facebook at AhramOnlineSports.)