Claudio Ranieri's Roma return was spoilt by Romelu Lukaku, whose goal against his old club sealed a 1-0 win for Napoli. (More Football News)
Ranieri was appointed Roma boss over the international break, with the 73-year-old coming out of retirement to take charge of the club for a third time.
Yet it was ex-Roma striker Lukaku who decided Sunday's contest at Stadio Diego Armando Maradona, with his 54th-minute effort sending Antonio Conte's team back to the top of Serie A.
Lukaku was well-placed to convert from Giovanni Di Lorenzo's cutback, bringing up his fifth Serie A goal of the campaign.
Roma, who had just two attempts and managed only 0.07 expected goals (xG) in the first half, woke up after Lukaku's goal, with Artem Dovbyk powering a header off the woodwork from a free-kick minutes later, but the visitors' comeback attempts proved fruitless.
Ranieri's next task is to rally his troops for a Europa League clash with Tottenham on Thursday.
Data Debrief: Ranieri's underwhelming return
There was no sign of an immediate upturn for 12th-place Roma, if they were hoping for a new-coach bounce.
Roma ended the first half with fewer than 70 successful passes (68). It is the first time they have had so few successful passes in the opening half of a league game since 2004-05.
With only three wins to their name in the league, they have won fewer than four matches in their opening 13 Serie A games for the first time since the 1978-79 campaign (also three).
And of course, it had to be Lukaku, who was leading their line last season, that delivered the hammer blow. The Belgium international has been involved in nine goals in Serie A this term (five goals, four assists). Only his former Everton club-mate Ademola Lookman, now a star at Atalanta, has contributed to more goals in the competition (seven goals, four assists).
