Midfielder Idrissa Gueye ended Benin Republic’s hopes of advancing in the Africa Cup of Nations (AFCON) as Senegal advance to semifinals.
After a goalless play for over an hour, Gueye started and finished a move in the 69th minute which saw Sadio Mane tee up his team-mate to score in Cairo.
Benin were reduced to 10 men in the 82nd minute when Olivier Verdon was sent off for a foul on Gueye.
Despite the numerical disadvantage, Benin Republic poured out in numbers in search of a possible equaliser.
But poor ideas in the final third was their undoing until the final whistle.
The Teranga Lions will meet minnows Madagascar or Tunisia in the semi-finals on Sunday in Cairo, with the two to play in another quarterfinal clash on Thursday.
Senegal are now two wins from winning the Africa Cup of Nations for the first time.