Tunisia defender Dylan Bronn scored an own goal as Senegal secured a spot into the AFCON finals.
Tunisia thought they would have a chance to equalise when Idrissa Gueye handled in the box, but the Ethiopian referee rejected their penalty appeals after checking the incident on the VAR monitor. It was the second caution of the knockout phase for the Napoli centre-back and triggered an automatic one-match suspension.
Tunisia coach Alain Giresse changed two of the side that eliminated Madagascar, promoting Mohamed Drager and Ayman Ben Mohamed and benching Wajdi Kechrida and Ghaylen Chaaleli. Senegal then took control and had three opportunities before half-time to end the deadlock and edge closer to the July 19 final.
Niang swivelled inside the box only to fire well wide and Mane rounded Hassen but his shot from an acute angle finished well off target.