Juventus' winless streak reached four matches with a 2-1 loss at Palermo on Wednesday that dropped the struggling 27-time champion into eighth place in Serie A.
Former Juventus striker Fabrizio Miccoli put Palermo in front seven minutes in with a shot under the legs of Italy goalkeeper Gianluigi Buffon, then Giulio Migliaccio doubled the lead in the 20th with a header off a corner.
Juventus argued for a penalty to no avail despite a clear handball by Palermo defender Cesare Bovo in the 34th, and Juventus midfielder Claudio Marchisio took his anger out over the missed call to cut the lead in half two minutes later with a shot that went by four defenders.
"There were fouls that were not awarded and a penalty not given that was devastating," said Juventus coach Luigi Del Neri. "We want respect. It's not that they need to give us all the penalties, but at least the clear ones."
Second-place Napoli lost 2-0 at Chievo Verona, which scored goals through Davide Moscardelli and Gennaro Sardo. AS Roma was held to a 1-1 home draw by Brescia, which equalized in the 69th through Brazilian striker Eder after Marco Borriello had put Roma ahead.
AC Milan, which drew 0-0 with Lazio on Wednesday, holds a five-point lead over Napoli, with Lazio seven points back and Roma nine points behind in fourth.
Five-time defending champion Inter Milan, which has played two fewer matches, is 10 points back entering its game at Bari on Thursday.
Also Wednesday, it was: Cesena 1, Catania 1; Fiorentina 1, Genoa 0; Parma 0, Lecce 1; Sampdoria 0, Cagliari 1; and Udinese 1, Bologna 1.
Juventus, which is 13 points behind Milan, has not been able to overcome a series of injuries that have decimated its attack, taking out Fabio Quagliarella, Simone Pepe and Luca Toni.
Juve signed Alessandro Matri as the transfer window closed Monday, and the former Cagliari forward played from the start but his best chance unluckily hit Bovo's heel in the 48th.
Juventus also lost 2-1 to Udinese at the weekend, and was eliminated 2-0 by Roma in the Italian Cup quarterfinals last week following a 0-0 draw with Sampdoria.
"We deserved more, but now we've got to start over," said Del Neri, who is in his first season with the Turin club. "We've got to make it clear that there needs to be more attention paid to Juventus right now by the refereeing department."