AC Milan hit the Serie A summit after victory away to title rivals Udinese, as Cagliari held on to beat Palermo at home.
A late fightback from Milan saw the reigning champions win 2-1 at Udinese and inflict a first home defeat of the season on their opponents.
Udinese took a deserved lead on 19 minutes through Antonio Di Natale's 17th goal of the season when his shot took a decisive deflection off Thiago Silva to beat Marco Amelia following an exchange of passes with Gelson Fernandes.
The hosts continued to control the match, but they were made to pay for not taking their chances in the 77th minute as Milan levelled with a rare counter-attack.
Stephen El Shaarawy's shot was pushed out by Samir Handanovic, who appeared to be in two minds whether to hold the ball or push it away, and substitute Maxi Lopez was on hand to net his first goal for the Rossoneri.
Milan grabbed a shock winner in the 85th minute with Lopez this time setting up El Shaarawy, who slid the ball inside the near post from seven yards.
Cagliari moved to within a point of Palermo on the back of a 2-1 home win over their opponents.
Mauricio Pinilla gave Cagliari the lead on 56 minutes and Daniele Dessena's goal nine minutes from time appeared to make the game safe.
Substitute Abel Hernandez pulled a goal back from the penalty spot two minutes later, but Palermo were unable to find an equaliser.