SERIE A leader Juventus was beaten 1-2 at home by 10-man Sampdoria and two other title contenders also lost on Sunday, as the big Italian clubs struggled to get back into full gear after the holiday break.
Juventus went all of last season unbeaten but has now lost four times this campaign.
Italy forward Antonio di Natale scored twice to help Udinese beat 10-man Inter Milan 3-0, and Fiorentina lost 0-2 to Pescara for its first home defeat of the season.
Also, Edinson Cavani was on form and scored a hat-trick as third-place Napoli beat Roma 4-1 in the late match. With 16 goals this season, the Uruguay forward moved two past Stephen el Shaarawy of AC Milan to top the league scoring chart.
AC Milan also struggled before beating Siena 2-0 with two second-half goals.