Napoli captain Marek Hamsik admitted the team's exploits this season have taken him by surprise, but he feels his side can mount a title challenge if they keep up their current form.
Hamsik and Co. preserved their 100 per cent record in the Europa League after five matchdays with a 1-0 win over Club Brugge on Thursday.
The away win continued Napoli's good form domestically and in Europe, having not tasted defeat since the opening day of the Serie A season in August - a run of 17 matches.
Napoli sit second in Italy's top flight and Hamsik says they have improved a great deal since last season.
"I honestly didn't expect Napoli to be this successful, although there was already some good material to work with last season," he told Sky Sport Italia.
"We can believe in winning the Scudetto if we continue to play well. There's a very long way to go, so we can't say, but if the results arrive and we keep playing like this, then we can believe in the title."
Napoli had already been assured of qualification as Group D winners prior to kick-off on Thursday and Vlad Chiriches added to their already impressive campaign with the game's only goal in the 41st minute.
"It was a difficult game psychologically, as we avoided a potential collapse in motivation seeing as we were already qualified and the stadium was deserted," coach Maurizio Sarri added.
"There were big risks and we were practically without any available strikers. The lads did well to nonetheless play a real game, so this is another clear step forward."