Guinea-Bissau handed the Super Eagles a heavy 3-0 defeat on Tuesday in their second Group L match of the 2027 Africa Cup of Nations qualifiers in Bissau.
The result was Nigeria head coach Eric Chelle’s first defeat since taking charge of the national team.
Guinea-Bissau took the lead in the 15th minute when Franculino Dju curled an effort into the far corner beyond goalkeeper Stanley Nwabali.
The Super Eagles struggled to respond before the break, prompting Chelle to make two changes at half-time. Moses Usor and Moses Simon replaced Frank Onyeka and Taiwo Awoniyi as Nigeria searched for a way back into the match.
The hosts, however, extended their advantage in the 66th minute through Mama Baldé.
Nigeria came close to reducing the deficit late in the game, but Guinea-Bissau goalkeeper Djoco Embadje denied George Ilenikhena with a close-range save in the 87th minute.
Álvaro Djaló then completed the victory for Guinea-Bissau with a third goal in the fifth minute of stoppage time.
The result leaves Guinea-Bissau top of Group L with six points from two matches after their earlier 2-0 victory over Tanzania.
Nigeria remain on three points following their 2-1 comeback win over Madagascar in their opening qualifier.
The Super Eagles will now look to recover in their next matches as their AFCON 2027 qualification campaign continues.