Roma fans will be barred from large sections of the Olympic Stadium for the home game with Inter Milan on March 2, Serie A chiefs ruled on Tuesday.
The decision extends an existing partial stadium ban after the club's unruly fans infringed "territorial discrimination" rules by targeting Napoli with derogatory chants.
Roma were initially handed a two-game partial ban two weeks ago after chants directed against Napoli and the club's supporters, meaning the north and south stands of the Olympic Stadium were closed to fans.
Roma served the first of those sanctions on Sunday during a 3-0 win in a half-empty stadium over Sampdoria.
However further derogatory chanting during Sunday's fixture has prompted the closure of sections of the stadium adjacent to the South Stand for the visit of Inter.
The sanction, which comes with an 80,000-euro ($110,000) fine, came after fans again targeted Napoli with the song: "Wash them, wash them, wash them with the fire from Vesuvius."
It is a reference to Mount Vesuvius -- the volcano which overlooks the city of Naples and whose eruption in AD 79 led to the destruction of Pompeii -- and has often been sung by fans of rival clubs to antagonise and provoke the Napoli support.
However, it is now considered unacceptable by Italian football authorities as they try to clamp down on racism as well as the territorial discrimination that has marred internal football rivalries for decades.