Striker Edinson Cavani scored a superb hat trick to give Napoli a 3-1 home win over defending Serie A champion AC Milan Sunday. Milan went ahead with an Alberto Aquilani header but it took less than two minutes for Uruguay forward Cavani to spring into action with the equalizer. Cavani, who scored 26 Serie A goals as he helped Napoli finish third last season and qualify for its first Champions League campaign, added two more either side of halftime. Napoli joined Juventus, Udinese and Cagliari on six points from two games while Milan was left languishing alongside Inter on one point. Alessandro Matri scored early in the second half to give Juventus a 1-0 win at Siena, having been set up by Montenegro striker Mirko Vucinic, one of its new signings. Udinese needed only half an hour to finish off Fiorentina as Antonio Di Natale, league top scorer last season, converted a penalty and Chile midfielder Mauricio Isla added the second in their 2-0 home win. Cagliari beat promoted Novara 2-1 in Sardinia Saturday when Inter was held 0-0 at home by AS Roma in a match between two sides struggling to find their feet under new coaches Gian Piero Gasperini and Luis Enrique. Sebastian Giovinco scored twice, including a last-minute winner, in Parma's 2-1 win over Chievo but the home winger was sent off in injury time after picking up a second yellow card for playing on after the whistle. Genoa won 2-1 at Lazio and Atalanta beat Palermo 1-0, Argentine forward German Denis scoring in a match in Bergamo which was interrupted by torrential rain for more than half an hour in the second half. Deducted six points for their part in a Serie B match-fixing scandal, promoted Atalanta are unbeaten and have minus two points.