Inter Milan were crowned Serie A champions on Sunday after they won 2-1 at Siena and nearest rivals Roma lost 2-1 at Atalanta.
Victory left Inter on 84 points, 16 ahead of Roma with five games left to play.
2006 FIFA World Cup™ winner Marco Materazzi scored twice for the visitors - the second a twice-taken penalty - as Inter retained the scudetto for their 15th Italian championship.
Without the threat of perennial rivals Juventus and AC Milan, Inter encountered few difficulties in the league this season with Roma the only club offering some kind of threat.
"It's an immense emotion," Nerazzurri coach Roberto Mancini told SKY Italia. "The squad have been extraordinary. To win the championship with five games to go is incredible. The team have shown great character."
After a tentative start, Inter went ahead in the 18th minute. Dejan Stankovic delivered a corner from the left which found Maicon. The Brazilian wingback's effort was cleared off the line by Paolo Negro, but only as far as Materazzi, who stabbed home from close range.
Inter's joy was shortlived as Siena restored parity three minutes later. Daniele Galloppa's left-wing cross was knocked back across goal by Leandro Rinaudo, and Negro stooped to head the equaliser.
Alex Manninger prevented Inter from regaining the upper hand with a superb flying save in the 33rd minute to keep out Zlatan Ibrahimovic's powerful header. Inter were grateful to Julio Cesar in the 49th minute, the Brazilian keeper keeping out Negro's goalbound back-heeled shot with his foot.
The visitors continued to press and they restored their lead on the hour. Manninger brought down Julio Cruz in the penalty box and the referee pointed to the spot. Materazzi scored only to be told to retake his kick due to encroachment, but the defender held his nerve to find the net again.
Roma, who were without their injured captain Francesco Totti, fell behind in the 37th minute at Atalanta when Cristiano Doni headed in a right-wing cross from Ferreira Pinto for his 13th goal of the season.
Riccardo Zampagna made it 2-0 to the home side just before half time with a contender for goal of the season. The 32-year-old striker picked up the ball from Doni with his back to goal, flicked it up with his right boot and then hooked it over the head of Roma keeper Alexander Doni.
Simone Perrotta hauled Roma back into the contest, but Atalanta managed to hold out for the three points.