Juventus clinched their third straight and 30th overall Serie A title on Sunday without even playing.
With second-place Roma losing 4-1 at Catania, Juventus' eight-point lead became insurmountable because Roma only has two matches remaining.
Juventus, which has three games to play, can celebrate when it hosts Atalanta on Monday although the Turin squad's players and coach Antonio Conte were already seen celebrating outside their team hotel wearing championship T-shirts.
The title was a bit of a consolation for Juventus after it was eliminated from the Europa League semifinals by Benfica on Thursday - missing out on the final in its home stadium.
In Sicily, Mariano Izco scored for Catania in the 26th and 34th minutes. Gonzalo Bergessio also netted for the hosts in the 55th after Roma captain Francesco Totti pulled one back in the 37th. Then Pablo Barrientos added another for Catania in the 79th.
The loss ended Roma's nine-match winning streak, and the Giallorossi put up little resistance against a Catania side fighting to avoid relegation.
Roma, which had already clinched second place and the last direct Champions League berth, was hoping to keep the title race open until next weekend when it hosts Juve. However, Roma coach Rudi Garcia said Saturday the title race was over and complimented Juve on its near-perfect season.
"We did everything wrong today," Roma coach Rudi Garcia said. "The only thing I didn't get wrong was when I said yesterday that the season was over. Although I wasn't expecting a match like this. ... I'll expect a response next Sunday."
Juventus has won all 17 of its home matches and lost only two away games.
Argentine striker Carlos Tevez leads Juventus with 19 goals in 31 matches and, with 15 goals, Spanish forward Fernando Llorente has also been decisive.
Both Tevez, who signed from Manchester City, and Llorente (Athletic Bilbao) joined Juventus before the start of this season.
Juve's defense featuring Italy stalwarts like goalkeeper Gianluigi Buffon and defenders Giorgio Chiellini, Andrea Barzagli and Leonardo Bonucci was just as solid. And midfield maestro Andrea Pirlo is still performing near his best at 34.
There was controversy two years ago when Juventus celebrated what it claimed was its 30th title, although it actually only had 28 championships then since two were revoked following a 2006 match-fixing scandal.
It's the first time Juventus has won three straight since taking five consecutive titles from 1931-5.
Elsewhere Sunday, it was: Chievo Verona 0, Torino 1; Genoa 0, Bologna 0; Parma 2, Sampdoria 0; and Udinese 5, Livorno 3.
The Milan derby was scheduled for later.