Grasshoppers saw a second Swiss Super League match called off in the space of six weeks after fans reportedly told players to hand over their shirts, shorts and socks in Sunday's game with Luzern.
Switzerland's most successful club were trailing 4-0 at Swissporarena, a result that was set to seal their relegation to the second tier for the first time in 70 years.
The match was halted in the second half when a large number of visiting fans moved to the front of the stand, causing riot police and stewards to form a line blocking their access to the pitch.
After Grasshoppers officials and players spoke to the crowd, some supporters demanded they remove their kit as they were not deemed worthy to wear them, according to reports in the Swiss media.
Some of the players eventually handed over their shirts and the game was called off
The 27-time Super League champions later issued a statement condemning the behaviour of the fans concerned.
"It's the second time within a few weeks that one of our games had to be stopped because of fan riots. That is shameful and simply unacceptable," they said in a statement.
"Grasshoppers understand the frustration with the sporting performance of the team. [But] violent acts and unsportsmanlike behaviour, which leads to a game being suspended, are again condemned by the club in the strongest terms."
The club also called on police and the Swiss Football Association (SFV) to work to prevent any repeats of such incidents.
Grasshoppers' match with Sion in March was abandoned after fans threw firecrackers and flares onto the pitch, leading the home side to be awarded a 3-0 victory.
A similar forfeit will confirm their relegation to the Challenge League, with Grasshoppers sitting 12 points adrift at the foot of the table with three games to go.
