Juventus, who defeated Milan 2-0 at home earlier in the season, are level with the champions on 34 points from 16 matches but with a worse goal difference. Udinese are third on 32 points.
In the remaining round of matches postponed from the opening day of the season because of a players' strike, Lazio stayed fourth on 30 points but continued their poor home form with a goalless draw against mid-table Chievo Verona.
Napoli reacted to Sunday's home defeat by Roma with a spectacular first half display to blow away Genoa and remain joint sixth on 24 points.
AS Roma's good away form continued at Bologna as first half goals from Rodrigo Taddei and Pablo Osvaldo gave Luis Enrique's side an easy 2-0 win to keep pace with Napoli.
Palermo's new coach Bortolo Mutti saw a debut victory slip from his hands as Novara came back from two goals down to draw 2-2 with Marco Rigoni equalising six minutes from time.
Gianluigi Buffon blocked Udinese's best chance from Chilean winger Mauricio Isla early on with the draw ending Udinese's 100 percent home record.
"There are draws and draws and we've now played against five of the top six sides away from home," he told Italy Sky Sport channel. "We're unbeaten and I'm happy.
"If someone had told me in July that we would finish the year without losing I would have thought he was mad.
"You need to prepa
