Inter survived a minor scare to lift their fifth successive Serie A title and stay on course for an unprecedented Italian treble after a tense but deserved 1-0 win at already-relegated Siena on the final day of the season.
Argentina striker Diego Milito finished coolly on 57 minutes after great work from compatriot and captain Javier Zanetti to leave team mates in tears at full-time and controversial coach Jose Mourinho pointing to the sky.
Second-placed Roma won 2-0 at Chievo thanks to Mirko Vucinic and Daniele De Rossi and would have been champions had the final games of the season finished at half-time.
Inter topped the final standings on 82 points, two above Claudio Ranieri's side, and next meet Bayern Munich in Saturday's UEFA Champions League final in Madrid having also won the Coppa Italia by beating Roma earlier this month.
The Nerazzurri's title triumph was the perfect present for club President Massimo Moratti, celebrating his 65th birthday. Whether Mourinho is his coach for his next birthday remains to be seen with Moratti admitting before kick-off he does not know what the former Porto and Chelsea boss will do after Saturday.
Media speculation is rife that the Portuguese will move to Real Madrid given he has openly acknowledged he is unhappy in Italian football and has repeatedly said he wants to coach a big Spanish club having won titles in Portugal, England and Italy.
Mourinho joked after Inter's Cup final win that Roma would pay Siena to beat his side. The Tuscan club's owner Massimo Mezzaroma, who comes from Rome and whose name translates as "half Roma", laughed off the remarks but his relegated team showed real desire to hurt Inter.
Siena's Albin Ekdal missed a glorious early chance with the visiting defence all at sea. Inter, roared on by a majority away crowd in Tuscany, settled into their rhythm with surprise starter Mario Balotelli acrobatically rattling the bar and Milito going close.
Further north Chievo's stadium in Verona was filled with the red and yellow colours of Roma fans, who had peacefully passed Inter supporters going in the other direction on the motorway.
The atmosphere exploded with wild cheers five minutes before the break when Vucinic fired in from just inside the area. De Rossi then blasted in from distance on the stroke of half-time to make it 2-0 and prompt crazed away fans to wave their giant flags in the hope Siena could continue to hold out.
Siena were denied a penalty early in the second period when the ball brushed Thiago Motta's arm but Inter were soon in the ascendancy again and Milito finally broke through with a superbly calm finish with the outside of his boot.
The dependable Argentine striker, who has netted 22 Serie A goals in his first season since signing from Genoa, screamed with delight and could not stop running before being engulfed by joyous team mates.
Siena, though, could easily have equalised late on.
Inter's achievement of winning five Scudetti in a row equals the record set by Juventus in the 1930s but the first of Inter's championships in that run could yet be struck off.
They received the 2006 title in a courtroom after original winners Juventus were demoted following the Calciopoli scandal.
New evidence has emerged in the criminal trial linked to that affair four years ago which Juve say shows for the first time that Inter were implicated in the scandal and so the 2006 title should be stripped from them as well. Inter deny wrongdoing.
Sampdoria were also celebrating on the final day after Giampaolo Pazzini's second-half goal secured a 1-0 home win over Napoli and the fourth and final Champions League qualifying spot ahead of Palermo.
The Genoa-based club, whose boss Luigi Del Neri has been strongly linked to Juve in the media, have only played in the European Cup once before when they reached the 1992 final.