By ESPNSTAR.com staff
The Neapolitans were the better side for much of the game but a late double four minutes from time earned Bologna a surprise win.
Mazzarri could only watch on as his side failed to consolidate the result as Federico Agliardi put in a man-of-the-match performance and repeatedly denied the Napoli attackers.
The result now leaves Napoli eight points behind league leaders Juventus after the Bianconeri strolled to a 3-0 win over 10-man Atalanta earlier on Sunday.
The Italian manager conceded that Juve have just been too good for the Serie A this season and dismissed the tag of title contenders attributed to the Partenopei this season after the home loss.
"The whole ‘Anti-Juventus' thing is a slogan the media thought up and I'm sick of it. Juventus are doing something extraordinary and I've said since the summer that we have to grow," he told reporters in the post-match press conference.
"We're all on a par now for second place and will see how the season ends, as I don't see anyone else right now who can compete with Juve.
"Maybe things will change, but it's tough when they're playing like that. We should focus on other objectives."
He also bemoaned his side's inability to bury their chances and called for more aggression on their behalf during the match.
"Napoli created many scoring opportunities and Bologna scored on one of only two chances they had in the first half.
"Our defect is that once we take the lead, we think the job is done. It has happened many times and we don't finish sides off.
"We get distracted and unconsciously the players think the victory is safe. That is where we really must improve and make that step up in quality, otherwise we'll keep dropping points continually.
"I have tried to tell my players they play too ‘nice' and need to be more determined. I hope we can learn from these lessons."
Napoli are also embroiled in a match-fixing scandal after former goalkeeper Matteo Gianello claimed to have discussed terms on helping Sampdoria win a game against them back in 2010. Mazzarri dismissed the claim as being a fanciful assertion and is hoping for a positive outcome in Monday's trial although his side could also be docked points as a result of the investigation.
"We are hopeful for tomorrow [Monday]. The fact is the entire case is just one person's word against that of two others.
"Is that enough to ban players? Besides which, I don't think these lengthy bans for not alerting authorities is entirely fair."