The 31-year-old missed his side’s 0-0 stalemate with Reims due to a muscle strain injury but returned to help the Red and Whites clinch their first win of the season.
Aleksandr Golovin opened the scoring in the 29th minute of the game and Slimani thought he had doubled the lead a minute later but the Video Assistant Referee (VAR) cancelled his effort for offside.
Patrick Burner then levelled for Patrick Vieira’s men in the 54th minute before Slimani set up Golovin for his second goal in the game.
Wissam Ben Yedder then found the net with 10 minutes left to play to ensure Leonardo Jardim’s men ended their six-game winless run.
Slimani featured from the start to the finish in the game along with his compatriot Youcef Atal, who ended on the losing side.
The on-loan Leicester City striker, who had scored three league goals this season, will hope to maintain his fine form when Monaco take on Brest in their next game on Saturday.