Juventus crashed to their third consecutive defeat to leave coach Ciro Ferrara under severe pressure after a 2-1 loss at home to Catania.
The Sicilians picked up their first win over Juventus in more than 45 years thanks to a penalty from Jorge Martinez midway through the first half and a winner from Mariano Izco three minutes from time. Hasan Salihamidzic had given Juve some hope in the 66th minute, but it was not enough to prevent another defeat for the Bianconeri.
Inter Milan moved eight points clear of AC Milan after a 1-0 win against Lazio at the San Siro.
Samuel Eto'o tapped Inter ahead on the rebound in the 14th minute after Lazio keeper Fernando Muslera had palmed out a header by the Cameroonian.
Lowly Lazio rallied in sub-zero temperatures at the San Siro but, apart from an appeal for handball against Maicon in the area, they created few clear chances for all their possession.
Roma enhanced their prospects of a Champions League place with a 2-0 victory over top-four rivals Parma at the Stadio Olimpic.
Nicolas Burdisso scored early in the second half before Matteo Brighi added a second late on to lift the Giallorossi above Parma on goal difference and ensure a positive end to 2009 for Claudio Ranieri's side. Parma ended the game with 10 men after Massimo Paci was sent off for a second bookable offence three minutes from time.
Livorno slowed Sampdoria's charge for European football and picked up three vital points for themselves as they came from behind to win at the Armando Picchi Stadium.
Antonio Cassano had put Sampdoria ahead after 15 minutes, but Nelson Rivas equalised six minutes before the break and Tomas Danilevicius had Livorno ahead early in the second half. Samp piled forward in a desperate bid to end a barren run away from home that stretches back to September 13, but instead it was Danilevicius who sealed victory with an injury-time strike.
Palermo maintained their impressive form under new coach Delio Rossi with a narrow win over Siena that propelled them to the verge of the European places in Serie A, as Edison Cavani netted the winner at La Favorita.
Napoli's impressive run of results continued as they ended the year in sixth place thanks to a comfortable victory over in-form Chievo.
The Partenopei got off to the perfect start when Marek Hamsik fired them into an early lead from the spot after German Denis had been fouled by Chievo goalkeeper Stefano Sorrentino. And Fabio Quagliarella secured all the points three minutes from time.
Genoa v Bari and Udinese v Cagliari were postponed due to the bad weather that hit the country on Saturday.