The draw left Inter in second place on 39 points, 10 behind runway leaders and title holders Juventus, who beat Palermo 2-1 on Saturday.

Roberto Mancini's side are now in threat of being leapfrogged by city rivals AC Milan, who have 37 points and will host Parma later on Sunday.

Inter began the game in an explosive style and pinned the hosts in their half but couldn't create any scoring opportunities.

In the second-half, the Milan giants laid siege on the Sienna box and produced more chances but strikers Adriano, Obafemi Martins and their successors Julio Cruz and David Pizzaro squandered them all.

In other matches, Lazio produced a 4-1 drubbing of Ascoli, Livorno beat Sampdoria 2-0, Roma edged Treviso 1-0, Chievo and Messina downed Lecce and Empoli 3-1 respectively.