Juventus fans aimed racist chants at Mario Balotelli during a Primavera youth team match against Chievo.
A few Bianconeri supporters have consistently insulted Balotelli, even when they were not playing Milan.
This latest incident is particularly serious, as the racist abuse was heard during a game between teenage players.
It was the Final Eight of the Primavera tournament, which saw Juve beaten 2-1 by Chievo.
Youth academy director Gianluca Pessotto had to walk over to the stands in order to calm the situation and beg for them to stop after the referee halted play as a warning.
The official protocol in Italy is for the referee to stop play for a few minutes and let a message be read over the tannoy system warning the game will be abandoned if racist chants continue.
This news comes after a survey showed Juventus supporters notched up more fines than any other Serie A club this season.
Their misbehaviour cost a total €327,000 for the club, whereas Siena were the best fans with just a €3,000 fine.