Soccer: 'Perfect' Roma stay top
Leaders thrash Bologna 5-0 for sixth consecutive win30 September, 11:24
The win gives Rudi Garcia's team a maximum tally of 18 points from six games.
Napoli and champions Juventus share second place, with 16 points each, after beating Genoa 2-0 and Torino 1-0 respectively.
Controversy followed Juve's victory over their city rivals as Paul Pogba's winning goal should have been disallowed because of offside by Carlos Tevez in the move that led to it.
Genoa, who are 15th with four points, sacked coach Fabio Liverani and reappointed former boss Giampiero Gasperini following the defeat.
Inter slid to fourth with 14 points after being held to a 1-1 draw against Cagliari.
Their injury-hit city rivals AC Milan climbed to ninth with eight points thanks to a laboured 1-0 home win over Sampdoria.