Lorenzo Insigne’s early strike proved enough, as Roma hit the woodwork twice, but Napoli conquered the Olimpico for an eighth straight win.
There were big expectations for this Derby del Sole, as the Partenopei had a perfect start to the season, winning all seven games with 25 goals scored, while the Giallorossi were finding their feet with five consecutive victories in all competition. Edin Dzeko and Dries Mertens were battling for the Capocannoniere crown again, but the hosts missed injured Stephan El Shaarawy, Kevin Strootman, Gregoire Defrel, Emerson Palmieri and Patrik Schick. Diego Perotti, Lorenzo Pellegrini and Daniele De Rossi shook off knocks to start.
Coaches Maurizio Sarri and Eusebio Di Francesco both play 4-3-3, but have very different interpretations, albeit focusing on attack, possession and entertainment. The record between the tacticians going in was perfectly even: three wins each and three draws, scoring 14 goals apiece.
A wicked Aleksandar Kolarov corner completely surprised Pepe Reina, but was cleared practically off the line, but it was Napoli who were more effective in the final third.
After Alisson smothered a Mertens angled drive at the near post, the Belgian’s assist for Insigne ricocheted off De Rossi and the Italian kept his cool to finish from 12 yards. It was Insigne’s first goal against Roma, but above all the 100th of his professional club career. It was also the 200th Napoli have scored in Serie A under 84 Maurizio Sarri matches.
Dzeko couldn’t get enough power or precision on his header from the Bruno Peres cross, but Alisson at full stretch palmed a Marek Hamsik cross into the path of Insigne, whose shot was deflected wide.
Mertens took down a long ball with remarkable skill, but went down far too easily as he was approached by Juan Jesus. Insigne dribbled through a crowd in the box only to be cut off as he was pulling the trigger, then there were concerned faces on the touchline as Mertens fell awkwardly on to his left shoulder.
Straight after the restart, Dzeko blasted over following a Faouzi Ghoulam error, as did Kolarov from distance, but Mertens failed to make the most of a Kostas Manolas stumble when he drilled across the face of goal. The Greek defender picked up a muscular problem in that move and had to be replaced by Federico Fazio.
Alisson smothered a Hamsik strike and Roma started to get more possession, but were ineffective, a Lorenzo Pellegrini cross deflected over Reina.
The first Reina save came on 70 minutes, as on a corner Fazio was allowed a free header from 10 yards and the Spaniard fingertipped it on to the near post.
The hosts poured forward in droves, a Kolarov free kick flashing past everyone in the six-yard box, but Pellegrini also went off with a thigh injury.
Alisson showed excellent reactions to deny Insigne, but he was offside anyway. Dzeko came so close to an equaliser moments later, his glancing header from a Kolarov corner thumping the top of the crossbar.
Cengiz Under flashed a cross-shot past the face of goal with Dzeko just unable to get there for the tap-in. Mertens was tackled in the box by Fazio, but the referee waved play on.
Deep into stoppages, Cengiz Under had the chance to equalise, but his volley from eight yards was straight at Reina.