Napoli shot to the top of Serie A with a controversial 3-0 win at 10-man Inter Milan on Saturday as Claudio Ranieri suffered his first defeat in charge and was sent off at halftime.
Earlier, Bojan, Pablo Osvaldo and Simplicio were on target as fourth-placed AS Roma beat Atalanta 3-1.
After an end-to-end start at Inter the game turned dramatically on an incident four minutes before the break when Joel Obi was handed a second yellow card for bundling over Christian Maggio on the edge of the box.
Julio Cesar saved Marek Hamsik's resulting penalty but defender Hugo Campagnaro followed up to give Napoli the lead.
Ranieri was sent off for remonstrating with the referee as the teams trooped off at halftime.
"He ruined a beautiful game," the Inter coach told Sky Sports. "He was not on his game. What he could get wrong, he did get wrong.
"The boys gave their all and should not have been punished in this way. I don't normally complain about these things but today was an exceptional occasion."
In a more subdued second period wing back Maggio added a second goal on 57 minutes, lifting the ball over Julio Cesar, before Hamsik slotted home the third with a quarter of an hour to go to seal Napoli's first victory at the San Siro in 17 years.
Inter have only four points from five games while Napoli, who finished third last season, go two points clear of Juventus, Udinese and Roma ahead of Sunday's main programme.