An Edinson Cavani hat-trick handed Napoli a 3-0 win over Lazio to keep pace with Serie A leaders Juventus as Milan finally broke their San Siro jinx by beating Cagliari 2-0 at home on Wednesday.
Cavani's first-half brace and third goal just after the hour meant Walter Mazzarri's side join Juventus in remaining unbeaten after five games, and put the Uruguayan top of the league scoring charts on five goals.
"I'm happy to have scored three goals, but the fact we've won is what matters," said Cavani, who brushed off suggestions Napoli could reproduce another challenge for the scudetto.
"I don't know if it will be a duel for the title with Juventus, but I do know it's too early to make the call."
Juventus had failed to build on their two-point lead on Napoli Tuesday when they dropped their first points of the season in a 0-0 draw away to an impressive Fiorentina.
Juventus and Napoli now sit joint top with 13 points and boasting the exact same goals for/against figures.
With Inter Milan winning 2-0 away to Chievo and Sampdoria drawing away to Roma, it means Lazio drop to fifth with AC Milan moving up to 10th after their first home win of the season.
Napoli had managed to beat Lazio only once in their last seven league encounters and early on it appeared the visitors had opened the scoring after German international Miroslav Klose bundled the ball into the net.
But after Napoli players reacted furiously, Klose admitted he had given the ball a helping hand over the line and the goal was disallowed.
It took Cavani only 19 minutes to settle nerves when he unleashed a long-distance missile which crucially deflected off Michael Ciani to beat the helpless Federico Agazzi.
Cavani grabbed his second by beating the offside trap to send a rocket over the top of the outstretched Agazzi on the half hour.
The Uruguayan then ran down on goal unchallenged and dribbled around Marchetti to score his third just after the hour mark.
Cavani could have had a fourth from the spot after second-half substitute Lorenzo Insigne won a penalty, however the Uruguayan skied his effort over the bar.
While Inter grabbed an important win away to Chievo to move up fourth, it was city rivals AC Milan who grabbed the San Siro bragging rights.
Neither team had won at the shared stadium this season, leading Milan coach Massimiliano Allegri to come under huge pressure in recent weeks.
Ironically, the 45-year-old coach was serving a touchline ban for protests made to match officials on Sunday when his team finally turned the corner.
Italy under-21 striker Stephan El Shaarawy scored both goals for the Rossoneri in a match which saw Brazilian Robinho, who has finally recovered from injury, come off the bench in the second half.
Allegri has shown a lot of faith in El Shaarawy this season, and the young Italian was quick to dedicate his goals to his coach.
"Absolutely, we're all right behind him," he said. "Allegri has shown a lot of confidence in me. I'm young, but I always try to give my best and tonight it finally paid off."
Roma, who on Monday were handed a 3-0 home win by league chiefs after the enforced postponement of their away match to Cagliari, took a first-half lead through club icon Francesco Totti.
He scored his 216th Serie A goal to sit level third in the all-time scoring chartes.
However Gianni Munari stunned the Olympic stadium with a 62nd minute equaliser and Sampdoria held on for a draw which means they are still unbeaten this season and in third place one point ahead of Inter.