Neapolitans have grown accustomed to such pathetic abuse but, on this occasion, Partenopei coach Maurizio Sarri couldn't resist a response, sticking his middle finger up at those insulting him and his players.
"I replied to a group of people who were spitting at the bus and insulting us for being Neapolitan," he explained afterwards.
"I would never make a gesture like that towards anyone for being a Juventus fan. The vast majority of Juventus fans are wonderful people and there was one in our hotel who we had a good laugh and joke with.
"I have no issue with Juventus fans. It was only with those who spat at us and insulted us for being Neapolitan."
Flipping some supporters the bird was a rather childish response from Sarri, unbecoming of a 59-year-old man in a position of such authority. It certainly didn't have any effect on the idiotic fans at which it was aimed.
However, Sarri and his side produced a far more impressive response to the abhorrent territorialism they are subjected to on an almost weekly basis inside the arena, one that really hit Juve's followers where it hurts.
Napoli's assignment was an arduous one. They had lost on their last six visits to Juventus Stadium but, as they trailed the Bianconeri by four points at the summit of the Serie A standings, they needed to win to reopen the title race.
The top-of-the-table clash never really caught fire and looked destined to end in a draw but, in the final minute of normal time, Kalidou Koulibaly rose majestically to power home a Jose Callejon corner to decide the game in the visitors' favour.
Bianconeri boss Massimiliano Allegri argued afterwards that both teams had been "terrible" but that was only half true. Juventus had been terrible; Napoli had been decent.
Indeed, the visitors had been wonderfully disciplined in defence, becoming the first side ever to prevent the Old Lady from having a single shot on target since moving into the Allianz Stadium in 2011, and the far more creative and ambitious side going forward.
This was the perfect riposte to the claim that Napoli were flagging down the final straight. They had finished the stronger of the two sides, following up their come-from-behind win over Udinese on the same night that Juve had surprisingly drawn at Crotone with a victory at the home of their title rivals, thus reducing the gap between the pair from six points to just one.
Now, there are questions being asked of Juve's levels of fatigue and a spiky Allegri didn't dismiss the allegation that his players look tired.
"We’ve played 57 games in each of the last four seasons,” the coach said at a press conference.
"The others are already out of everything in November, yet no-one says anything. When you play at the rate we do, I think it’s normal to be tired.
"We’ve used up a lot of physical and mental energy. I don’t have to be here to tell you the numbers, but we’ve played 57 games a season, so you can’t say anything about the players.
"You can’t criticise these lads on any grounds. If you do, you’ll also make me lose my patience, which I have plenty of."
There is no denying, though, that Allegri has some issues to address, not least the form of star man Paulo Dybala, who was awful at Crotone and even worse against Napoli, withdrawn after just 45 minutes of play.
The likely season-ending injury suffered by Giorgio Chiellini in the first half has also come at a most unfortunate time for Juve, who must face both Inter and Roma away in the final four rounds of the season.
Chiellini's leadership and experience would have been relied upon heavily in such testing fixtures and Medhi Benatia doesn't inspire quite as much confidence without the Italy international alongside him.
Indeed, there were even numerous reports in Monday's newspapers that Gianluigi Buffon's Michael Oliver-induced rage resurfaced in the dressing room after the Napoli loss, with the captain allegedly singling out Benatia – who conceded the fateful penalty against Real Madrid – for special scorn after losing Koulibaly for the goal
Buffon immediately denied those claims but while he, Claudio Marchisio and Juan Cuadrado have all been at pains to point out that Juve's destiny is still in their own hands, there is undoubtedly a sense that the momentum has shifted significantly.
Certainly, everyone associated with Napoli now believes that a first Scudetto since 1990 is possible.
There were fans in streams of tears at the full-time whistle at the Allianz Stadium, while at least 10,000 people turned up at the airport in the early hours of Monday morning to welcome their heroes back from Turin.
Even the mayor of Naples felt compelled to call for focus on the next round of fixtures after enjoying Sunday night's "beautiful and joyful party".
The whole city has been whipped into a frenzy by the last two rounds of results but it is worth noting that Napoli have some tough games to come themselves, starting at Fiorentina on Sunday.
Juve fans are also trying to lift their side's spirits, unveiling a banner at Vinovo on Monday that read: "Us with the voice, you with the heart - let’s win it!"
The Bianconeri certainly have the experience to recover from Sunday's setback and claim a seventh successive Scudetto.
"There are 20 days to go," Buffon mused, "and we’ll have to return to the pitch with ferocity and ‘sporting brutality’. We all have to be united."
Napoli have no such concerns, of course. They have an entire city behind them, a group of people united by a dream. Their passion could be either a help or a hindrance. Indeed, controlling their emotions will arguably be their toughest challenge - and Sarri's.
He let his anger get the better of him for a split-second in Turin but he will now know that keeping his cool to lead Napoli to just their third title would actually be the ultimate 'up yours' to those Juve fans that abused him, his players, his people and his city.