Rome: An injury-time goal from Genoa midfielder Luca Antonini handed Juventus their first defeat of the season Wednesday when a 2-0 win for Roma allowed the title challengers to pull level at the top of Italy`s Serie A.
Udinese`s 3-0 defeat at Fiorentina allowed AC Milan, held 1-1 at Cagliari, to move three places up to third with Sampdoria still in fourth despite suffering a last-gasp 1-0 defeat at Inter Milan.
Both AC Milan and Sampdoria are six points off the leaders` pace, with Udinese dropping to fifth, also on 16 points and one ahead of Lazio who face Verona on Thursday.
Gonzalo Higuain should have handed Napoli all three points in the dying minutes away to Atalanta but the Argentinian striker saw his spot-kick saved by Marco Sportiello.
Napoli remain seventh and are now seven points adrift of Juventus and Roma.
Juventus had moved clear of Roma last weekend after Rudi Garcia`s men were held to a scoreless draw away to Sampdoria but were frustrated at the Luigi Ferraris stadium where goalkeeper Gianluigi Buffon was making his 500th appearance in a Bianconeri jersey.
Carlos Tevez was the victim of a brutal foul by Aleandro Rosi in the opening minutes, the midfielder escaping without a booking despite a lunge which left the Argentinian writhing in pain.
Juventus spurned several chances, notably when home goalkeeper Matia Perin pulled off a superb one-handed save from Alvaro Morata at the death after he had replaced fellow Spaniard Fernando Llorento on 65 minutes.
The match looked to be heading for a draw until Antonini stunned Massimiliano Allegri`s men by bundling a cross from the left past Buffon after being left unmarked in front of goal.
It was Juve`s first league defeat in injury time since a reverse to Roma in 2010, and gave Garcia`s men a huge boost as they dominated Cesena at the Stadio Olimpico.
Lukasz Skorupski replaced Morgan De Sanctis in goal for the hosts and Seydou Keita returned to the midfield while Ashley Cole was brought in at left-back following a spell on the sidelines due to a dismal display in a 7-1 drubbing by Bayern Munich.
Mattia Destro replaced captain Francesco Totti and gave Roma the lead with an easy tap-in from Gervinho`s inch-perfect pass inside 10 minutes.
Destro had the ball in the net on 28 minutes when he fired a powerful header past Federico Agliardi, but was a fraction offside when he started his run to meet Miralem Pjanic`s free kick from the left.
Agliardi had to react quickly to keep Alessandro Florenzi`s corner from swerving into the net in the final 10 minutes, but from the resultant corner the `keeper was finally beaten a second time.
Mapou Yanga-Mbiwa had replaced Davide Astori on 54 minutes and did well to keep the ball in play at the byeline for Daniele De Rossi to bundle a volley home from close range.
In Bergamo, Napoli were stunned 13 minutes into the second half when German Denis ran in unhindered between Christian Maggio and Raul Albiol to nod Cristian Raimondi`s cross past Rafael.
Napoli should have levelled two minutes later but Jose Callejon somehow skied Ghoulam`s cross despite being less than a metre from goal.
Atalanta suffered a blow late on when Luca Cigarini saw red for a second bookable offence, and Napoli capitalised soon after when Higuain spun on Lorenzo Insigne`s pass into the area to beat Sportiello down low.
Napoli won a penalty in the dying minutes after Guglielmo Stendardo`s fool on Cristian Zapata, but Sportiello did well to keep out Higuain`s effort from 11 metres.