A hotly-contested penalty set Serie A leaders AC Milan on their way to a 3-0 home win over title rivals Napoli on Monday which extended their advantage at the top to five points.
Zlatan Ibrahimovic blasted home the spot-kick early in the second half after Salvatore Aronica was adjudged either to have handled or used an arm to block Alexandre Pato with replays inconclusive.
Napoli players went crazy at the decision, jostling the referee, but Milan felt justice was done after having two earlier penalty shouts turned down in a largely low quality game in heavy rain.
Substitute Kevin Prince Boateng made it 2-0 from Pato's pass on 77 minutes and Brazil striker Pato curled in an excellent third as a toothless Napoli barely threatened.
Third-placed Napoli's defeat meant champions Inter Milan stayed second after Sunday's 2-0 win at Sampdoria.