Juventus winger Federico Chiesa was sent off on his debut and the Serie A champions also had a goal disallowed by VAR for offside by the tiniest of margins as they were held to a 1-1 draw at promoted Crotone on Saturday.
Chiesa, signed from Fiorentina during the recent transfer window, was given a straight red card for a studs-up challenge on Luca Cigarini on the hour.
Juventus, missing Cristiano Ronaldo after he tested positive for COVID-19 on Tuesday, thought they had scored a winner when Alvaro Morata turned the ball in from close range in the 77th minute but a long VAR review showed his heel was offside.
Crotone had taken the lead with a Simy penalty in the 12th minute before Morata levelled from Chiesa's assist nine minutes later. Juve, chasing a 10th straight title, have eight points from four games while Crotone picked up their first point.
Earlier, Napoli blasted four goals in a devastating 20-minute first half spell as they thumped Atalanta 4-1, handing the visitors a taste of their own medicine.
Free-scoring Atalanta, last season's top-scorers with 98 goals, had netted 13 goals in winning their first three games but had no answer to Napoli's attacks in an extraordinary first half.
Mexican forward Hirving Lozano, out of favour with coach Gennaro Gattuso last season, set Napoli on their way with two goals in four minutes.
The player known as "Chucky" tapped in from Giovanni Di Lorenzo's cross in the 23rd minute and curled in the second after Dries Mertens pounced on a mix-up in the Atalanta midfield.
Matteo Politano fired the third on the half hour and Nigeria forward Victor Osimhen took advantage of more poor defending to score the fourth before the interval.
Napoli goalkeeper David Ospina's kick upfield was misjudged by Cristian Romero and Osimhen, signed from Lille in the summer, chested the ball down and scored with a shot on the turn to net his first goal for his new club.
Romero partially made amends by setting up Atalanta's consolation for substitute Sam Lammers in the 69th minute. The Argentine won possession, charged upfield and released Lammers who clipped his shot past Ospina.
Atalanta remained on nine points from four games, one ahead of Napoli.
Napoli have won all three of their games on the pitch, scoring 12 goals and conceding one.
However, Serie A's disciplinary committee handed them a 3-0 defeat for failing to play a match against Juventus amid confusion over the COVID-19 rules and they also had a point deducted.
Speaking about the missed game for the first time, Gattuso said: "I was angrier than anyone," he said, adding that Juve are rebuilding under new coach Andrea Pirlo and that he believed Napoli could defeat them.
"Juventus are the team to beat but, at the moment, they are a construction site. We were on the bus and ready to leave. I am angry that we didn't travel and I can assure you we did everything possible."