A friendly between AC Milan and Italian lower division football club Pro Patria was suspended after players walked off because of racist chants.
Milan's Kevin-Prince Boateng picked up the ball 25 minutes into the first half and kicked it into the crowd.
Ghana international Boateng then removed his shirt and was followed from Pro Patria's home pitch by both sets of players and officials.
There had been appeals for the abuse to stop from the public address announcer.
