AC Milan kept their three-point lead intact with a 2-1 win at Fiorentina on Sunday, while Napoli chased on after beating Bologna 2-0.
AC Milan were back to winning after they thrashed Inter 3-0 last week, and they brought the momentum to Fiorentina.
Alexandre Pato headed an assist for Clarence Seedorf's eighth- minute opener and the Brazilian turned scorer four minutes before half-time to double his side's lead.
Canadian Juan Manuel Vargas breathed life into Fiorentina's bid to win a point with 11 minutes remaining. Although Milan's Zlatan Ibrahimovic was sent off in the 87th minute, on his return from suspension, the visitors held on for victory.
Napoli's good form continued after they won 2-0 at Bologna, while Juventus came from behind to defeat Genoa 3-2.
Walter Mazzarri's side won their fourth match in succession thanks to first-half strikes from Giuseppe Mascara and Marek Hamsik.
Bologna had only lost at home in the league once since December so the task was never going to be easy for the Naples-based club, but Mascara gave his side the lead on the half-hour mark.
He was booked for his celebration in a tense match littered with cautions, with the most crucial yellow card of the match handed to Bologna goalkeeper Emiliano Viviano on the stroke of half-time.
Viviano was given a caution for his foul on Ezequiel Lavezzi and Hamsik buried the resultant penalty, giving his side a valuable two-goal advantage at the main break.
The cards continued to come in the second half but Napoli held on for an important away win.
In Torino, Juventus scored three second-half goals as they recorded an impressive 3-2 home win against Genoa.
Leonardo Bonucci's seventh-minute own-goal had the hosts on the back foot but they equalized through another own goal, with Marco Rossi putting the ball into his own net early in the second half.
That goal energized Juve and although Antonio Floro Flores hit the back of the net for Genoa after 57 minutes, goals from strike duo Alessandro Matri and Luca Toni -- the latter with seven minutes remaining -- saw Luigi Delneri's side record victory.
In other matches, Lazio moved ahead of Udinese and into fourth after a 2-0 home triumph over relegation-threatened Parma, thanks to goals from Hernanes and Sergio Floccari.
Struggling Sampdoria's horror run of form continued as they slumped to a 2-1 home defeat to Lecce, with David Di Michele and Ruben Olivera getting on the scoresheet for the victors.
Striker Massimo Maccarone pulled a goal back with 21 minutes remaining but it was not enough for Sampdoria, who lost key goal- scorers Antonio Cassano and Giampaolo Pazzini in the January transfer window and have now won just one of their last 14 league matches.
Cesena, who sit second from bottom, pulled off a remarkable comeback to draw 2-2 at Palermo.
First-half goals to Jasmin Kurtic and Mauricio Pinilla had Palermo seemingly cruising, but stoppage-time strikes to Marco Parolo and Emanuele Giaccherini saw the promoted side snare a famous draw.
As if the goals did not make the second half eventful enough, three Cesena players were shown red cards. Defender Steve von Bergen was dismissed on 74 minutes for a dangerous foul of Pinilla, with unused substitute Paolo Sammarco also red carded for leading the protestations.
Fellow substitute and veteran goalkeeper Alex Calderoni followed him down the tunnel in the 90th minute after overdoing the celebrations at Giaccherini's equalizer in the sixth minute of stoppage time.
Maxi Lopez's first-half equalizer gave Catania a point in a 1-1 draw at Bari. Brescia also came from behind to draw 1-1, at Cagliari.