Diego Milito broke his goal drought on Wednesday to help Inter Milan thrash Bari 4-0, while Roma slipped into the relegation zone as they were beaten 2-1 by Brescia.
Milito was on target for the first time this season as he and Samuel Eto'o hit doubles in Inters crushing win.
Eto'o surged into the penalty area from the left flank and crossed for Milito to head into the top left corner for the first in the 27th minute, and the second goal arrived in the 50th minute when Marco Rossi's handball from Wesley Sneijder's cross gave Inter a penalty, which Eto'o rifled into the right corner.
Eto'o hit the back of the Bari net again after 63 minutes, again from the 12-yard mark, after Lucio was pulled down by Emmanuel Rivas for a clear penalty and Dejan Stankovic's superb pass found Milito who thumped a fierce shot past goalkeeper Jean-Francois Gillet late on.
Rafa Benitez, coach of Inter, did not believe Inter are already running away with the Scudetto and hailed Diego Milito.
"It's not a breakaway run. The season is long and we are just at the start, but of course it is always nice to be on top," he said.
"Milito was already working very well for the team, but the only difference this time from the other games is that the ball hit the back of the net," he said.
Cesena, joint leaders with Inter coming into the fourth round, suffered their season-first loss after they were beaten 2-0 at Catania. Cesena lost their first Serie A game of the season as they crashed down to Catania in Sicily. Matias Silvestre was on target for the hosts in the 23rd minute before Maxi Lopez doubled the advantage in the 58th minute.
Perparim Hetemaj gave Roma a shock with 13 minutes into the game and Andrea Caracciolo's penalty in the second half virtually made the game safe as Philippe Mexes was sent off following his challenge. Marco Borriello netted a late consolation, but it was not enough for the Giallorossi.
Sergio Floccari's equalizer prevented AC Milan from returning to winning ways as Lazio earned a deserved 1-1 draw at the Stadio Olimpico. Zlatan Ibrahimovic had given the Rossoneri a 1-0 lead in the 66th minute only for Lazio to hit back with nine minutes remaining.
Milan were unlucky not to claim all three points after Gianluca Zambrotta's strike rattled the crossbar two minutes from time. The result marked Milan's second straight draw and their third game without a win under new boss Massimiliano Allegri.
Allegri insisted that his sides are improving and have the chances to overtake their cross-town rivals, who are five points ahead. of them.
"I liked the way Milan played, as the team worked hard and we didn't concede counter-attacks. If we had emerged with a victory, then we'd be here saying Milan rediscovered itself. We're on the right track," he said.
"The team worked well and we just need a victory, which hopefully will arrive on Saturday, but it was a good performance in my view.
"We just need to race ourselves and not anybody else. It's true we are behind, but for example Roma and Milan last season fought their way back from bad starts. It's a long season and we're just at the beginning," he added.
Sebastien Frey earned Fiorentina a point with a string of spectacular saves in his side's 1-1 draw at Genoa. Alberto Gilardino put the Viola ahead in the 11th minute but Giandomenico Mesto equalised for the hosts in the 18th minute. Frey then took centre stage to deny Genoa with five stunning saves to rescue a point for the visitors.
Bologna beat Udinese 2-1 in an early season relegation clash. Antonio Di Natale found the net for the Zebrette after just nine minutes but Henry Gimenez made it 1-1 seven minutes later. In the dying moments Marco Di Vaio popped with the winner for Bologna.
Chievo scored an impressive 3-1 win in Napoli. The Neapolitans surged to a 1-0 lead as early as the ninth minute through Paolo Cannavaro but the Flying Donkeys replied with three goals to win 3-1 in Naples. Sergio Pellissier restored parity midway through the first-half and scored again in the 74th minute. Gelson Fernandes was on target for Chievo on 58 minutes.
Cagliari were held to a scoreless draw at home by Sampdoria in a lackluster display.