Despite Senegal’s strong group position, they still fielded a formidable side that included some of their best players, yet failed to grab a hold of the game in the opening 25 minutes.
Benin still held hopes of securing a top-two finish, meaning there was still plenty on the line for Pape Thiaw’s side.
Senegal began to take over after a tense opening, and the deadlock was broken via a set piece five minutes before half-time.
Seck powered home a pivotal header following a brilliant whipped cross from midfielder Krepin Diatta, giving The Lions of Tarenga the lead despite a lengthy VAR check for handball.
Minutes later, their lead was nearly doubled as Diallo’s cross very nearly forced an own goal.
Senegal began confidently in the second half and went close through Diallo again, who was allowed acres of space to run into before shaping a curled effort just past the post.
With Sadio Mane causing chaos on the wings, he worked his way past three Benin defenders before firing a low cross for Diallo, who grabbed his ninth goal for his country.
It was all smooth sailing until the 71st minute when captain Kalidou Koulibaly was dismissed after a lengthy VAR check for a foul on the back of the Achilles, which left his side facing almost 20 minutes with a numerical disadvantage.
It didn’t stop them from adding a third late on as Cherif Ndiaye capped off a comfortable evening at the Tangier Grand Stadium, as he scored his fourth goal for his country, ensuring they qualify as group winners after two wins in three games.
Their reward is facing one of the best third-placed teams, in what should be a favourable draw. For Benin, the defeat means they finish as one of the highest-ranking third-placed teams, and they will progress into the next round, albeit with a far tougher draw.
Flashscore Man of the Match: Sadio Mane (Senegal)