Juventus retained their Serie A title with a 1-0 home win over struggling Palermo on Sunday.
The Turin club needed only a point to claim a second straight Scudetto - their 29th in total - but Arturo Vidal's 59th-minute penalty ensured they took all three.
Nearest challengers Napoli later saw off Inter Milan 3-1, thanks to an Edinson Cavani hat-trick, but with only three rounds of matches left the 11-point gap is now insurmountable.
Antonio Conte's men had to play the final seven minutes with 10 men after Paul Pogba saw red for spitting at Salvatore Aronica but that was the only blot at the end of what proved a decisive eighth league win in a row.
Juventus players celebrated with flags and placards bearing the number '31', a reference to the two titles they refuse to acknowledge were stripped from them in 2006 following a match-fixing scandal in Italy.
Palermo, meanwhile, have been plunged deeper in relegation peril.
They had picked up 11 points from their previous five matches heading to Juventus Stadium but fell three points off safety after Genoa boosted their own survival hopes and condemned bottom club Pescara to Serie B at the same time with a 4-1 victory.
Siena, who had defender Felipe sent off shortly before half-time for handball, are five points from safety after a Gonzalo Bergessio hat trick gave Catania a 3-0 win.
In the race for the third Champions League berth, third-placed AC Milan capitalised on Fiorentina's defeat at Roma on Saturday with a 1-0 home win over Torino.
Mario Balotelli struck the only goal of the game, his 11th since arriving at the club earlier this year, as Milan moved four points clear of fourth-placed Fiorentina.
Udinese's hopes of qualifying for the Europa League stayed alive after captain Antonio Di Natale's double helped seal a 3-1 win over Sampdoria.
Lazio remain two points behind Udinese after Miroslav Klose scored five - the first Lazio player to do so in a Serie A match - during a 6-0 rout of Bologna.
The day's other match saw Parma beat mid-table rivals Atalanta 2-0 with goals from Marco Parolo and Jonathan Biabiany.