Napoli missed the chance to climb above Roma into second place in Serie A after being forced to come from behind to earn a 2-2 draw with Sassuolo.
Dries Mertens headed Napoli ahead with his 22nd goal of the season but Sassuolo turned things around through Domenico Berardi and Luca Mazzitelli before Arkadiusz Milik earned a point.
Jose Callejon had the best opportunity of the first half after 31 minutes when he latched onto a cross from Mertens but he could only fire his shot into the side-netting from an acute angle.
Marek Hamsik fired inches wide after Lorenzo Insigne pulled the ball back, but Napoli finally broke the deadlock on 52 minutes when Mertens arrived at the back post to head home Callejon's cross via a deflection from Francesco Acerbi, who attempted to hack it off the line.
The lead though only lasted seven minutes before Beradi levelled after a howler from Hamsik. The Napoli skipper nodded the ball back towards Pepe Reina unaware of Beradi closing him down and he nipped in to prod it past the onrushing goalkeeper.
Sassuolo then went ahead after 80 minutes when Reina pulled off a great save to turn away Paolo Cannavaro's half-volley but - after the ball was played back into the box - Mazzitelli fired home.
However, Napoli earned a draw four minutes later as Milik netted from close range after Kalidou Koulibaly had headed down a Raul Albiol corner.