Napoli was relieved after Zambo Anguissa scored the dying miunute goal. Napoli celebrated that goal as if it was the finals that they succeeded in winning. It was a tough match for Napoli because their visitors sealed up their defense. I expect Napoli to improve their performance in the next match so that, they can easily win the match instead of struggling all through 90 minutes.
Napoli know that defending their Scudetto is hard and the other clubs in Serie A won't give Napoli any free Scudetto without challenge. Dropping any points will be harmful for their title defending task and Napoli have many reasons to celebrate that winning goal as 2 more points from it can contribute considerably to Scudetto competition in this season.
With Conte management since the last season, Napoli aimed at winning matches in whatever ways and results as most as they can. Earned points are more important than how they play and how many goals they score or how impressive or not impressive in their winning.