To those present at Cagliari’s Stadio Sardegna on Sunday, the sounds were familiar.

As Inter Milan’s new Belgian striker, Romelu Lukaku, stepped up to kick what would turn out to be a match-winning penalty, Cagliari fans behind the goal engaged in a prolonged round of monkey chants. They continued as the shot by Lukaku, who is black, struck the back of the net.

The outburst was not the first of its kind in the arena — Cagliari fans racially abused a black Juventus player last season — and it was swiftly condemned after video of the incident circulated on social media. But much of Italy seemed to react with a shrug of the shoulders. Cagliari defended its fans’ honor in a statement. League officials announced that at least for now, there would be no discipline. Even Inter’s fans defended the behavior in a letter to their new star.

The message to Lukaku, who joined Inter from Manchester United in August, seemed to be: Don’t take it personally, this is Italy.

The ugly incident was not the first episode of racist behavior in Italian soccer, but the reaction to it highlighted efforts to brush such behavior under the carpet. When the young Juventus striker Moise Kean was subjected to similar abuse at Cagliari last season — one of a string of high-profile cases recently at the stadium — his coach and one of his teammates initially blamed him for provoking it.