High-flying Juventus held by Parma while Atalanta edged out Genoa in Wednesday's Serie A action.
Juventus would have moved top with the three-point haul against Parma, but were held to a goalless draw.
AC Milan lead the way after beating Udinese on Saturday but the draw, Juve's 10th in 22 league games this season, left them a point behind the Rossoneri.
The Old Lady still have a game in hand, though, and did at least maintain their unbeaten run this season, extending it to 25 matches in all competitions.
Juventus dominated the first half and should have had an early lead. Giorgio Chiellini got up to meet Andrea Pirlo's free-kick but his header bounced off the base of the post.
The rest of the half involved lots of Juve probing but few concrete chances. Arturo Vidal looped a high ball into the box and Alessandro Matri got up to meet it but his header lacked power.
Pirlo came inches away from producing something special but his free-kick from 20 yards flew just past the post.
Parma came out with more purpose after the break and created their first chance as former Juve forward Sebastian Giovinco, following a swift counter, forced Gianluigi Buffon into a sprawling save.
The whole second period took on a different shape, with Parma far more positive and Juve struggling to create anything of note.
Juve started to click towards the end of the game but still couldn't find the breakthrough.
Elsewhere, Atalanta edged Genoa 1-0 in Serie A to claim their first home win since December.
Substitute Guido Marilungo struck 12 minutes from time to hand the Bergamaschi their second victory in seven games.
Genoa were unlucky not to go in front in the 58th minute when Juraj Kucka's header from a corner struck the crossbar with Atalanta goalkeeper Andrea Consigli already beaten.
But the result in Bergamo has lifted Atalanta to 13th in the standings, nine points clear of the relegation zone. Genoa remain in 10th place, still searching for their first win away from home since December.
The game had been scheduled to be played earlier this month but was postponed due to heavy snow in Bergamo.