Coach Maurizio Sarri said Juventus "didn't deserve to win" after his first game on the bench ended in a painful goalless draw at Fiorentina Saturday with three players going off injured to complicate preparations for next week's Champions League opener.
But Serie A rivals Napoli won at home thanks to a Dries Mertens double in a 2-0 victory over crisis club Sampdoria, before hosting Liverpool on Tuesday.
Sarri missed his team's first two wins over Parma and Napoli with pneumonia, but four days before Juventus travel to Atletico Madrid in the Champions League his side failed to impress in Tuscany.
"We wouldn't have deserved to win this game," said Sarri of a game where Portuguese star Cristiano Ronaldo and his teammates lacked inspiration up front and struggled physically.
The reigning eight-time Serie A champions are already missing injured captain Giorgio Chiellini, Mattia De Sciglio and Marko Pjaca.
And Brazilian Douglas Costa pulled up with a hamstring problem minutes into the game in Florence, as Miralem Pjanic hit with a muscular issue just before the break with Danilo suffering cramps in the heat.
They nevertheless held on despite pressure with former French international Franck Ribery impressive on his first start for the hosts.
"It was a very complicated situation as we used all our substitutions for injuries, and had no fresh players to introduce at key moments," said Sarri.
"It was not a high-level game from a technical point of view, a team with less character would lose such a game."
Midfielder Rodrigo Bentancur added: "We got an important point, today we saw a bad Juventus.
"We suffered on the wings, they were very good. We still have to get used to Sarri's game, but we are on the right track. Now we want to win in Madrid."
Ribery, 36, went off to a standing ovation from the crowd at the Artemio Franchi Stadium after an hour as his team earned their first point this season.
Ribery "played better than Ronaldo," insisted Fiorentina's new owner Rocco Commisso, as the French player did well to neutralise Ronaldo, who had scored four goals for Portugal in European qualifiers this week.
"I hadn't played a game like this for almost three months," said the former Bayern Munich player. "We had few chances but Juve are a great team and it was very hot."
Juventus had a chance to break through in the 74th minute when Sami Khedira raced down the right to serve Ronaldo, only for German Pezzella to intercept.
Ronaldo's acrobatic bicycle kick in the 85th minute, failed to hit the mark flying over the bar as Juventus settled for a point.
Juventus are top of the table with seven points from three games but Inter Milan can move ahead when they host Udinese later on Saturday.
In Naples, Carlo Ancelotti's side were playing their first home game after renovations carried out to their San Paolo Stadium.
Giovanni Di Lorenzo provided the cross for Mertens to tap in after 13 minutes.
New signing Fernando Llorente made his debut midway through the second half and the former Tottenham player set up the second, sending the ball back to Mertens who finished off a shot which took a slight deflection off Sampdoria defender Alex Ferrari.
"We did well, especially in the first half," said Ancelotti.
"Today those who entered did well, played quality football, this is important for our growth. So we are a team.
"Llorente and (Lorenzo) Insigne gave the team a good boost.
?We kept a clean sheet, so at least that was a sigh of relief," he added after Napoli conceded seven goals in their first two games against Fiorentina and Juventus.
Napoli move up to fourth in the table as Eusebio Di Francesco's Sampdoria remain stuck to the bottom of the table with no points after three games.