Martin Odegaard continued his fine start to the season as Premier League champions Arsenal kicked off their Champions League campaign with a fine away win.
The Gunners captain only scored three times last season but his fourth in five appearances this term won the game in Naples.
A fine angled drive with 15 minutes left was enough for Mikel Arteta’s side to come away with three vital points.
The Gunners claimed maximum points from each of their eight games last season on the way to the final and impressed again.
Massimiliano Allegri’s side opened their Serie A campaign with a 2-0 win away at Genoa, but they have since lost consecutive matches against Como and Inter Milan.
Bukayo Saka went close with a fine overhead kick before Kevin de Bruyne tested David Raya at the other end.
Mikel Merino had a powerful header tipped over after Ebe Eze headed across goal as Arsenal turned the screw.
It was a wonderful stop from Alex Meret, who was then early beaten by Eze after a flowing attack but the England man dragged his shot wide of the near post.
Saka then wasted the best chance of the half when Odegaard slid him behind the Napoli defence but he lifted his shot over the top
Napoli had to change their keeper at the break as Vanja Milinkovic-Savic replaced the excellent Meret, and Piero Hincapie then wasted a great chance for the Gunners when he slashed over the top.
It was looking like being a frustrating night in Naples before substitute Christos Tzolis teed up Odegaard for a lovely strike in off the far post.
Noni Madueke should have wrapped up the win with a late counter before De Bruyne threaded a fine ball across goal but no Napoli player was able to convert.
Kai Havertz then tapped home in added time but he was offside – but the Gunners held on to win.