Italy have not been crowned champions of Europe since 1968
Italy moved two points clear at the top of Group H as Daniele De Rossi hit the winner before being sent off against Bulgaria in a Euro 2016 qualifier.
Roma midfielder De Rossi, 32, scored from the penalty spot after Veselin Minev tripped Antonio Candreva.
Both teams finished with 10 men, De Rossi sent off with Bulgaria's Iliyan Mitsanski after the pair clashed.
Norway are two points behind Italy in second place after a 2-0 win over Croatia in Oslo.
With two games remaining, two of Italy, Norway and Croatia – third in the table with 15 points – can still secure automatic qualification.
Italy entertain Norway in their last game in Rome on 13 October.
In the group's other game, Azerbaijan drew 2-2 at bottom club Malta.
How Group H looks after Sunday's results