Terem Moffi netted twice, just as Oghenekaro Etebo, Simon Moses, and Ademola Lookman got one each in the tie.
Watford star Emmanuel Dennis, who was introduced in the later stages of the match, grabbed a goal to complete the demolition in the game played in Morocco.
Last week, Jose Peseiro’s men had beaten Sierra Leone 2-1 in Abuja to open their 2023 AFCON qualifier.
The Super Eagles now top the Group A standings with six points, followed by Guinea Bissau on three but with a game at hand.
With five goals on Monday, Osimhen is now the top scorer in the qualification game for the competition billed for next summer.
Nigeria’s next game in the race for the biennial showpiece is in September when they take on Guinea Bissau.
Super Eagles Head Coach, Jose Peseiro had said at Aeroport Agadir Almarissa that the encounter against ‘The Falcons and True Parrots’ would bring the best out of his team as they seek to go top of the Group A table.
He had said;
We want to be the team at the top of the table, so we must fight hard against the opponents. Every match, we must commit ourselves fully to winning it. As I said earlier in the week, Nigeria have huge pedigree and they also have both quality and quantity of players. It is important that we select the best all the time to win the big games.
Defender and deputy skipper William Ekong and midfielder Innocent Bonke had returned to their respective bases in England and France to attend to injuries copped during the international break.
Bonke was injured in the friendly game against Mexico in Dallas on May 28, while Ekong suffered a groin strain in the 2-1 defeat of Sierra Leone in Abuja on Thursday.