Juventus head coach Andrea Pirlo questioned the "dubious" penalty awarded to Napoli and claimed his side are treated differently to other Serie A clubs.
Lorenzo Insigne scored the only goal of the game from the penalty spot after Giorgio Chiellini caught Amir Rrahmani in the face with a flailing arm.
That was one of only two shots on target Napoli managed in Saturday's 1-0 win at Estadio Diego Armando Maradona, compared to six for Juve - five of those in the second half.
And Pirlo, who saw Juve lose for the second time in five league matches to drop more points in the Scudetto race, felt his side were hard done by.
"They barely had a shot on goal and we lost through a dubious decision," he told Sky Sport Italia. "We played a good game but did not get the result we deserved.
"We played the ball around but not quickly enough, allowing Napoli to get back. We created more chances in the second half but did not find the goal."
Asked to elaborate on why he considered the 31st-minute penalty to be dubious, Pirlo said: "If you give a penalty for that then any contact in the box is punishable.
"If that had been given for us there would have been a lot of controversy and complaints, though I don't know if we would have been given a penalty in a situation like this."
Juventus have had five penalties in Serie A this season, putting them level with Roma and Sassuolo and behind only Milan, who have had an incredible 14.
Alex Meret, a late addition to Napoli's starting line-up after David Ospina sustained an injury in the warm-up, made six saves to frustrate Juve in front of goal.
Cristiano Ronaldo had four on-target shots kept out, while Alvaro Morata had a goal disallowed for an infringement by Chiellini - making his 400th Serie A outing - in the build-up.
But rather than blame his attackers for firing a blank, Pirlo instead credited Meret for standing firm between the sticks.
"My players played the game they had to," he said. "It is normal that playing so many games close together means a loss of sharpness.
"But both those who started and came on from the bench had an excellent game. The only thing lacking in the end was a goal.
"There's no guarantee the team that scores the most goals then wins the Scudetto.
"We create plenty of chances and the Napoli goalkeeper was man of the match, so I can't complain about my strikers today."
Napoli's victory was their first in four matches and eases the pressure on boss Gennaro Gattuso, who was reportedly set to be sacked had his side lost again on Saturday.
However, Gattuso - a former team-mate of Pirlo's for club and country - insisted he never doubted the backing of his players and staff.
"We showed great heart and determination," he said. "Juve deserved something more, but my team was under pressure and fought hard to keep the clean sheet.
"I never had doubts on this squad, otherwise I would've packed up my things and gone home.
"You can't get anywhere without the faith of the players. I always felt they were ready to do what I asked and that’s what matters."