Maurizio Sarri believes Napoli were on par with Juventus in Saturday's Serie A encounter in Turin and were unfortunate to lose 1-0.
Napoli appeared to be on their way to a scoreless draw until Simone Zaza found the net in the closing stage of the game to gift Juventus the full three points.
The defeat saw Napoli lose top spot in the table to Juventus, but Sarri feels they put in a strong performance irrespective of the final result.
"It was a very even game with few chances. It's a pity that we conceded shortly before the final whistle," the Napoli coach said at a news conference.
"We have to remain calm. A deflected shot will not destabilise us. We put in a good performance. It's quite rare that Juventus hardly create any chances in a home game. We could perhaps have done more going forward, but this was a good performance.
"There are very few teams in Europe that come to this stadium and are on par with Juventus, but we did just that. We conceded a goal when they were playing with just one attacker. But we have to accept the result and move on. There are plenty of positives.
"We must react right away. We have to learn from games like this in order to become a big team."