Monaco have been issued a three-point deduction (one suspended) and ordered to play one match behind closed doors following crowd trouble, the Professional Football League (LFP) confirmed.
The Principality-based outfit were punished for supporters' actions during the aftermath of the 2-1 victory over Le Mans in May.
The incident occurred after Claudio Ranieri's men were officially crowned Ligue 2 champions, when the home supporters invaded the pitch which resulted in the referee being hit by a fan.
The LFP released a statement illustrating why the punishment has been carried out, which read: "Behaviour of Monaco fans: the use of pyrotechnics, the pitch-invasion at the end of the match and the brutality towards the referee by one supporter."
Monaco are widely expected to launch a title charge this season having spent big to bring in the likes of Radamel Falcao, James Rodriguez and Joao Moutinho to Stade Louis II during the summer.