Guinea-Bissau defeated Nigeria 3-0 in their 2027 Africa Cup of Nations qualifying Group L match at the 24 de Setembro National Stadium in Bissau on Tuesday.
Franculino Djú opened the scoring for the hosts in the 15th minute, firing a left-footed shot past Nigeria goalkeeper Stanley Nwabali after being played into the box by Renato Nhaga.
Nigeria came close to an equaliser before half-time, with Alex Iwobi setting up Ademola Lookman, but Guinea-Bissau goalkeeper Embadjé made a fine save.
The hosts continued to threaten after the break and doubled their advantage through Mama Baldé in the 65th minute.
Baldé received the ball from Mamadi Camará on the left before firing a low shot into the net.
Nigeria made changes in an attempt to reduce the deficit, with George Ilenikhena and Raphael Onyedika replacing Akor Adams and Wilfred Ndidi in the 75th minute.
However, the Super Eagles could not find a way back into the match.
Ilenikhena came close to pulling one back in the 85th minute, but Embadjé produced another save to deny the Nigerian forward.
Guinea-Bissau sealed the victory in stoppage time when Álvaro Djaló scored the third goal after receiving a through ball from Tamble Monteiro and finishing with his right foot.
The defeat leaves Nigeria with work to do in their qualifying campaign, having beaten Madagascar 2-1 in their previous Group L match.