Juventus missed the chance to join Inter Milan at the top of Serie A after losing 3-1 at promoted Napoli following two dubious penalties on Saturday.
Alessandro Del Piero, who became a father on Monday after bagging the winner against Genoa last weekend, opened the scoring for Juve straight after the break when keeper Gennaro Iezzo fumbled his close-range effort into the net.
Napoli hit back quickly as Walter Gargano cut through the defence to blast home a powerful shot from inside the area.
Maurizio Domizzi then converted two penalties on 62 and 70 minutes after Giorgio Chiellini was harshly adjudged to have fouled Ezequiel Lavezzi and former Juve striker Marcelo Zalayeta appeared to dive over keeper Gianluigi Buffon.
"It is so clear they were not penalties. If everybody can see it how is it possible the referee cannot see it?", Juve president Giovanni Cobolli Gigli told Sky television.
STINGING SHOTS
The first half was even after Domizzi headed straight at Buffon while David Trezeguet and a below-par Sergio Almiron had stinging shots saved at the other end.
The visitors, with coach Claudio Ranieri banned from the bench after being sent off last weekend and Pavel Nedved suspended, also had a Trezeguet strike ruled out for offside.
Juve remained on 17 points following their second league defeat, three behind champions Inter who face a tricky trip to Palermo on Sunday. Stuttering AC Milan host fourth-placed AS Roma while Fiorentina in third visit Genoa.
Napoli, who went bust in 2004 before securing successive promotions to return to the top flight, are up to fifth.
Earlier, Torino beat Cagliari 2-0 thanks to Alessandro Rosina and a Michele Ferri own goal.
Forward Rosina had a simple finish after Roberto Stellone's pass took a deflection into his path midway through the second half and Ferri diverted a late corner into his own net.
Torino, who lost Alvaro Recoba early due to injury, struck the woodwork twice in the first period while Cagliari's Daniele Conti hit the post with a low free kick in the second.
