There were wins for defending champions Juventus and Inter Milan in Serie A on Sunday but Roma suffered defeat at home to Bologna.
Juventus had to come from behind to defend their lead in the standings after Ciro Immobile put Genoa in front in the 18th minute.
Emanuele Giaccherini brought the Bianconeri level after an hour, while Mirko Vucinic and Kwadwo Asamoah added a second and a third to make it three wins out of three for Juve.
Inter Milan sit fifth in the table after a 2-0 win which ended Torino's unbeaten run in Sunday's late kick-off in Italy.
Diego Milito opened the scoring in the 13th minute and substitute Antonio Cassano wrapped up the points in the 83rd minute.
The victory allowed Inter to bounce back from the defeat by Roma in their previous outing.
Napoli also claimed a 3-1 win to maintain their 100% start against Parma.
Walter Mazzarri's men were in control from the moment Edison Cavani netted a third minute penalty and, with Goran Pandev and Lorenzo Insigne also on target, Marco Parolo's strike was rendered worthless.
Lazio are third after a 3-1 win over Chievo at the Stadio Marcantonio Bentegodi.
Hernanes was the star of the show, scoring twice in either half, while he also set up Miroslav Klose for his strike for Vladimir Petkovic's side.
Sergio Pellissier netted a late penalty for the hosts.
Sampdoria also boast three wins from three after a 3-2 triumph at Pescara.
Maxi Lopez gave Samp the lead, which was doubled by Marcelo Estigarribia in the second period.
Mervan Celik pulled a goal back for the hosts with 15 minutes left before Lopez netted again and Gianluca Caprari scored a late consolation.
Bologna came from two goals down to claim their first points of the season with a 3-2 victory over shellshocked Roma at the Stadio Olimpico.
The Giallorossi looked to be cruising when Alessandro Florenzi and Erik Lamella struck in the first 15 minutes, but two goals in as many second-half minutes from Alberto Gilardino and Alessandro Diamanti brought Bologna back on level terms.
And there was one final twist in the dying seconds when Gilardino grabbed his second of the match after an embarrassing mix-up in the Roma defence.
Goals in each half from Steven Jovetic and Luca Toni handed Fiorentina all three points with a 2-0 win against Catania at the Stadio Artemi Franchi.
Montenegro forward Jovetic put the hosts ahead just before half-time and veteran striker Toni sealed victory moments after stepping off the bench.
Udinese were two goals in front after just five minutes but were held to a 2-2 draw by Siena, who hit back with a pair of second-half strikes following Andrea Lazzari's red card.
Dusan Basta put the visitors ahead after three minutes with a powerful effort, with Antonio Di Natale doubling the lead soon after from close range.
But the game changed when Lazzari received a second caution after 52 minutes as first Emanuele Calaio (70) and then Ze Eduardo, with a 77th-minute penalty, scored for Siena.