Some of the fans who swarmed onto the pitch managed to shout insults and even aim kicks at players, including Nicolas Pepe, the Ivory Coast forward whose goal had earned Lille a draw in the game at the Stade Pierre-Mauroy.
The supporters — around a hundred in total — then gathered by the entrance to the tunnel, below where incredulous directors were watching on, but were held back by stewards.
The result left Lille in the relegation zone — champions as recently as 2011, the northern side are at serious risk of going down to the second tier, a level they have not been at since 2000.
President Gerard Lopez, the Luxembourg-born businessman who bought the club last year, was in the stands and television cameras caught him shaking his head in disbelief at the scenes that marred the end of the game.
He had hoped the appointment of Marcelo Bielsa ahead of this season would help the club compete towards the top end of the table but the enigmatic Argentine was sacked late last year due to the team s poor form.
Bielsa has contested his sacking, seeking as much as 18 million euros ($22.2m) for wrongful dismissal.
Meanwhile, the club s financial situation was deemed so unhealthy that French football authorities recently inflicted a transfer embargo.
Christophe Galtier was appointed coach during France s winter break but has only managed two wins in 10 league games so far.