Bastia have closed the stand from which its fans twice invaded the pitch and attacked Lyon players in a French Ligue 1 match last weekend that was abandoned at half time.
After legal complaints filed by two Lyon players on Monday the Corsican club closed the stand and promised to upgrade security.
The club, vowing it won't be "taken hostage by a minority", has also promised that everyone involved will be identified and is pursuing police action.
Bastia said that the "Jojo-Petrignani stand" -- from which the pitch invasions were launched before Sunday's game and again at half time -- would undergo a security overhaul before its reopening to maximise safety at the Armand-Cesari stadium.
Already rock-bottom of the French top flight, Bastia go before a French League disciplinary commission on Thursday hoping against a heavy penalty.
"I cannot see the leaders of French professional football punishing the entire club because of what a few dozen people did," Bastia president Pierre-Marie Geronimi told RMC Radio station.
Geronimi added that a member of the stadium staff accused of colluding in the attack had been fired.
Sunday's game was called off at the break with the score at 0-0 but no one was arrested at the ground.
Riot police later fired tear gas to disperse a mob of Bastia fans waiting for the Lyon team coach to leave the stadium.
The French league's disciplinary commission is certain to hit Bastia hard after it docked them one point -- suspended -- and ordered the club to close its East Stand for three games over racist abuse directed at Nice striker Mario Balotelli earlier this season.