Ancelotti was speaking after his side was beaten 1-0 by Internazionale in Milan on Boxing Day in a league game that was marred by racist chanting towards Napoli's Senegalese defender Kalidou Koulibaly and fan violence before the match in which a 35-year-old man reportedly died.
The Napoli coach pointed to Koulibaly's dismissal in the 80th minute as the game's turning point, suggesting the defender had been severely "shaken" by the abuse.
"The red card determined the result. We were pushing towards the end but we were affected by going down to 10 men," Ancelotti told the Napoli website.
"It's a shame because three times we asked for the match to be suspended for the racist chanting towards Koulibaly."