Napoli boss Carlo Ancelotti said his team asked three times for their match at Inter Milan to be suspended because of alleged racist chanting, before a last-minute goal gave Inter victory.
Ancelotti claimed Kalidou Koulibaly was targeted at the San Siro, where the Senegal defender was sent off.
Lautaro Martinez scored a 91st-minute winner for Inter, before Napoli also saw forward Lorenzo Insigne dismissed.
"The next time we'll stop playing, even if we lose the match," Napoli coach, Ancelotti said.
"What happened today is not good not only for us but also for Italian football as a whole," the former Chelsea boss added.
"I'm very sorry about what happened to Koulibaly. The boy was on edge, he is an educated footballer who was targeted. Despite our requests, the match was not interrupted. I'm unhappy because three times we asked for the match to be suspended."
Koulibaly, 27, was sent off after receiving two yellow cards in a matter of seconds in the 80th minute. The first was for a foul on Matteo Politano, the second was for sarcastically applauding the referee's decision.
After the match he posted on Twitter: "I'm sorry about the defeat and especially to have let my brothers down.
"But I'm proud of the colour of my skin. To be French, Senegalese, Neapolitan, and a man."