Inter Milan sealed their 20th Italian title by beating arch-rivals and nearest challengers AC Milan in a historic Derby della Madonnina.
Francesco Acerbi was unmarked to head in Benjamin Pavard's flick-on from a corner to give Inter the lead.
Marcus Thuram latched onto a long ball and was given too much time to cut in before smashing their second into the bottom corner at the San Siro.
England's Fikayo Tomori headed in from close range to give Milan brief hope.
There were three red cards in injury time as tempers boiled over. Milan's Theo Hernandez and Inter's Denzel Dumfries were sent off for their part in a brawl and the hosts ended with nine men as captain Davide Calabria was sent off for violent conduct.
Inter players and coaches ran on to the pitch to celebrate at the final whistle at the ground both sides share, although Milan were the home side for this fixture.
The second-placed Rossoneri are now 17 points behind Inter with five games to go.
Inter could have won by more with Lautaro Martinez missing a sitter and Hakan Calhanoglu's drive being tipped over by Mike Maignan.
This was the first time the Serie A title has ever been won in the 116 years of the Milan derby.
"I feel like crying because we worked so hard, we deserve this joy," said captain Martinez, who has scored 25 goals in all competitions this season.
"It's been wonderful but we have to keep going because we've already won a lot of trophies and we want to win many more."
Inter back on top
Inter Milan's 20th Italian crown takes them above AC Milan's 19 Serie A titles and only below Juventus.
But this was only their second title since 2010, last winning under Antonio Conte in 2021.
Simone Inzaghi has brought the good times back to the Nerazzurri, cruising to the Scudetto with five games to spare on the back of a 27-game unbeaten run in the league.
They have scored 79 goals, 15 clear of anybody else, and conceded only 18, eight fewer than any other side.
Inter have now won the last six derbies, equalling the record runs of Milan from 1911-1913 and 1946-1948.