SIENA - And there's number two! Inter beat Siena 1-0 to add the Scudetto to the Coppa Italia on Massimo Moratti's 65th birthday.
Roma won away to Chievo but all Inter needed to do was match their result for a fifth consecutive Serie A title and eighteenth overall.
We're now a Champions League final away from completing a historic treble.
It was relatively plain sailing from start to finish in Siena but Inter survived a scare in the sixth minute when Ekdal fired wide with just Julio Cesar to beat after receiving from Codrea and turning Maicon in the box.
The Nerazzurri soon stepped into their stride and produced two clear chances inside a minute with Balotelli sending inches wide his first-time shot from Maicon's cross, before Milito narrowly missed the target after being put through by Balotelli.
Siena goalkeeper Curci saved close-range headers from Milito and Thiago Motta, and got down at his near post to block Eto'o's effort from the tightest of angles as Inter kept up the pressure.
The hosts raised their game when news filtered through that Roma had taken the lead against Chievo and Maccarone severely tested Julio Cesar with a ferocious left-footed drive from 25 yards.
Balotelli was unlucky not to give Inter the lead seven minutes before the break when he saw his stunning shot on the turn from Maicon's cross come back off the crossbar.
The Bianconeri produced a third clear chance ahead of the interval and Inter had Samuel to thank for blocking Jajolo's low shot.
Mourinho's men continued to outplay their opponents after the restart Zanetti surged past two players and laid off to Milito, whose brilliant 20-yard strike was tipped over by Curci.
Cambiasso was presented with a decent chance minutes later, his low drive from Eto'o's pass going just wide of the Curci and his left-hand post.
It was only a matter of time before the goal, and it came in the 57th minute when Zanetti powered his way past two Siena players and passed low to Milito who used the outside of his right foot to prod beyond Curci for his 22nd goal of the Serie A season.
Inter produced several clear chances to increase their lead. Substitute Stankovic shaved the bar with a trademark long-range effort, and Milito was denied by Curci with the flag going up for offside after Pandev's rebound went in off the Siena keeper.
First the Coppa Italia, and now the Scudetto. Vamos a Madrid!
Siena 0-1 Inter (HT: 0-0)
Scorer: Milito 57.
Siena: 85 Curci; 87 Rosi, 6 Terzi, 29 Cribari (15 Brandao 46), 3 Del Grosso; 10 Codrea (7 Reginaldo 81); 18 Ghezzal, 8 Vergassola, 12 Ekdal, 24 Jajalo; 32 Maccarone (11 Calaiò 54).
Subs not used: 89 Ivanov, 9 Malagò, 22 Tziolis, 23 Jarolim.
Coach: Alberto Malesani.
Inter: 12 Julio Cesar; 13 Maicon, 23 Materazzi, 25 Samuel, 4 Zanetti; 8 Thiago Motta (27 Pandev 54), 19 Cambiasso; 45 Balotelli (5 Stankovic 58), 10 Sneijder (26 Chivu 73), 9 Eto'o; 22 Milito.
Subs not used: 1 Toldo, 6 Lucio, 11 Muntari, 17 Mariga.
Coach: José Mourinho.
Referee: Emidio Morganti (Ascoli Piceno).
Booked: Del Grosso 11, Cribari 17, Brandao 64, Codrea 65, Chivu 85, Toldo 90+2.