Balotelli scored the opening goal in Sunday's encounter, before Lazio went on to claim a 2-1 victory thanks to Ciro Immobile's brace after Andrea Cistana had been sent off.
Shortly after Balotelli's goal, a warning was read out over the stadium's public address system after chants appeared to be targeting the Italy international.
Balotelli hit out at those responsible in an Instagram post that accompanied a clip of his goal, with the striker writing: "Lazio fans that were today [Sunday] at the stadium, SHAME ON YOU #saynotoracism."
Sconfitta che fa male ma ci rifaremo siamo sulla strada giusta. Laziali presenti oggi allora stadio VERGOGNATEVI! #saynotoracism✊🏾🤬 Is a lost that hurt but we will come back stronger and we are on the right way! Lazio fans that were today at the stadium SHAME ON YOU! #saynotoracism ✊🏾
The league agrees the chants were of a discriminatory nature and have issued a punishment, though Lazio avoided harsher sanctions due to their assistance in the investigation.
A Lega Serie A statement on Wednesday read: "Lazio was penalised an amount of €20,000 ($22,234) for having its supporters, in the 21st and 29th minutes of the first half, emitting a chant of racial discrimination against a player of the opposing team, in addition to an insulting chant against the same player in the 21st, 29th and 42nd minutes of the first half, which led the referee to interrupt the game to make the announcement aimed at the termination of the aforementioned discriminatory chant.
"The transmission of more detailed elements has also been arranged by the federal prosecutor, both with regards to the actual positioning (sector or sub sector)…of the supporters within which the leaders of this chant were placed, also regarding the active collaboration of Lazio in identifying the subjects involved in this discriminatory event, for the purpose of the possible adoption of further measures by this judge regarding the incident, and in any case also in relation to the evaluation of the possible recidivism."
This was not the first occasion Balotelli has been the target of abuse since returning to hometown club Brescia at the start of the season.