"It's complete rubbish. Winning our next games is the most important". The result pushes the Neopolitans into the top spot of Group C, whilst PSG remains in third place.
However, Napoli and Liverpool still have to play each other, while PSG, in theory, have the easier run in: Liverpool at home and Red Star away.
The match ended with Neymar furious with Dutch official Kuipers, who had handed him a yellow card for apparent protests that Napoli players were not the correct distance away while he was waiting to take a free-kick.
The result leaves things finely balanced in Champions League Group C, where Napoli top the table on six points, level with Liverpool who suffered a surprise 2-0 defeat in Belgrade against Crvena Zvezda.
PSG goalkeeper Gianluigi Buffon, making his Champions League debut for them after completing a three-match ban from last season, did not have a save to make in the first half of his first match in Italy since leaving Juventus.
DF Marquinhos, 7 - Cool and collected for the most part, he formed part of a back three that largely functioned well.More news: Record number of women win in the House
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MF Juan Bernat, 7 - Was not undeserving of his goal as part of arguably his best performance since his summer arrival.
He is likely to make the squad, but is not certain to start against his former team, with Angel Di Maria in form and ready to line up alongside Kylian Mbappe and Neymar.
FW Kylian Mbappe, 6 - Teed Bernat up for the opener, he was lively and one of PSG's most serious goal threats.
FW Neymar, 8 - Despite a late booking, he was largely excellent - particularly in the first half.
FW Eric Maxim Choupo-Moting, NR - Sent on at the death to add an extra attacking element, he barely got on the ball in the short time he was on.