Maurizio Sarri had a disappointing touchline debut with Juventus in a 0-0 draw at Fiorentina as the eight-time defending champion dropped their first points of the Serie A season.
Fiorentina's Franck Ribéry, Federico Chiesa and unheralded 22-year-old Gaetano Castrovilli caused problems for Juventus but the Tuscan squad could not quite finish off its numerous chances.
Sarri had watched Juventus' opening two matches from home with pneumonia and the coach will surely will not like what he saw up close Saturday.
The Bianconeri seemed to struggle with their fitness after the international break.
Juventus stalwarts Douglas Costa and Miralem Pjanic each limped off with apparent hamstring injuries in the first half and newly signed right back Danilo exited with cramps midway through the second.
Heat was a factor with the temperature inside Artemio Franchi stadium reaching 32 Celsius (90 F), prompting cooling breaks to be held midway through each half.
The closest Cristiano Ronaldo came to scoring for Juventus was a bicycle kick effort that went high in the 85th — although he was judged offside anyway.
Still, Juventus moved atop the table with seven points, one more than Inter Milan and Torino.
Fiorentina picked up their first point under their new owner, cable television businessman Rocco Commisso.
Inter can move top with a win over Udinese later while Torino host promoted Lecce on Monday.
Juventus play their Champions League opener at Atletico Madrid on Wednesday.
