Soccer: Perfect Roma five points clear after Juve collapse
Rossi scores hat-trick in Fiorentina's 4-2 win over champs21 October, 10:41
Roma have 24 points from eight games after a double by Bosnia midfielder Miralem Pjanic enabled them to maintain their perfect record in Friday's encounter.
Juve, meanwhile, looked to be cruising when they were 2-0 up with two thirds of the game gone on Sunday, but Fiorentina staged a remarkable comeback with a goal by Spanish midfielder Joaquin and a hat-trick by Italy forward Giuseppe Rossi.
For Rossi it was his eighth goal so far this season, after a two-year injury nightmare caused by two major knee problems.
Juve and Napoli share second place with 19 points each.
Promoted Hellas Verona are fourth with 16 points after they continued their good form with a 3-2 win over Parma.
Inter have 15 points and share fifth place with Fiorentina after being held 3-3 at Torino.
Atalanta climbed to seventh with a 2-1 home win over Lazio and AC Milan are eighth, having scraped a 1-0 victory over Udinese.