Idrissa Gana Gueye grabbed the winning goal to defeat Benin 1-0 and send Senegal into the last four of the Africa Cup of Nations.
The Everton midfielder started and finished a move which saw Sadio Mane tee up Gana to score in Cairo with 69 minutes on the clock.
Benin's Olivier Verdon was sent off in the closing moments of the game for a foul on Gana, who earned his 63rd cap for his country.
Aliou Cisse's team will meet minnows Madagascar or Tunisia in the semi-finals on Sunday in Cairo.
