The Liverpool superstar took the ball off team-mate Boulaye Dia’s foot after the Reims striker had rounded the
goalkeeper. But Mane could only find the side netting with his first-time effort.
Sadio Mane misses an open goal but made up for his howler by scoring an 82nd-minute winner to book Senegal’s place at the 2022 Africa Cup of Nations.
Cutting in from the left, Mane exchanged passes with Habib Diallo before poking the ball past Guinea-Bissau’s goalkeeper Jonas Mendes.
The goal was Mane’s 21st for the Lions of Teranga.
He is now just eight goals behind ex-Wolves and Wigan striker Henri Camara’s record of 29 for his country.
Mane was also on the scoresheet against Guinea-Bissau when the two sides’ met on Wednesday in the reverse fixture – a 2-0 win for Senegal.
Sunday’s victory made it four wins from four for Aliou Cisse’s side in AFCON qualifying.
They became the first team to qualify for the continental showpiece after hosts Cameroon.