Sassuolo's three points from Sunday's win over Pescara have been handed to their opponents after Serie A ruled the former had used an ineligible player.
Antonino Ragusa had signed for Sassuolo from Cesena last week, and made his debut as a 65th-minute substitute in the 2-1 victory.
However, it has since emerged that the attacker - who used to ply his trade at Pescara - had not been registered in time.
Serie A confirmed the news on Tuesday, with Pescara awarded a 3-0 win, moving them on to four points while Sassuolo remain on three.
Sassuolo director Giovanni Carnevali subsequently stated his club's intention to appeal the ruling.