AC Milan were held 2-2 at struggling Torino on Sunday, leaving city rivals Inter Milan three points clear at the top of Serie A.
Torino's Alessandro Rosina scored a 78th-minute penalty, which was conceded for handball by Kakha Kaladze, to earn the hosts a draw after Ronaldinho had put Milan 2-1 up with a spectacular free kick in the 34th.
Milan's Brazil striker Alexandre Pato had controlled a Gennaro Gattuso pass and thumped the ball home in the 29th to equalise shortly after Torino's Roberto Stellone opened the scoring with a glancing header.
The visitors rode their luck after Ronaldinho's strike and Rosina's late leveller was deserved, although Milan also had a good penalty claim for handball by Francesco Pratali turned down at the start of the second half.
Second-placed Milan have 27 points from 13 games, while champions Inter have 30 after Saturday's 1-0 win over third-placed Juventus at the San Siro.
"We should control the game better when we are in front," Milan coach Carlo Ancelotti told Sky television.
"The game was too open. We attacked, they counter-attacked, which was not ideal given that we were ahead and could have more cover."
Napoli are level with Juventus on 24 points after being held 2-2 at home by Cagliari earlier on Sunday.
Daniele Conti scored a stoppage-time equaliser for the Sardinian side after Ezequiel Lavezzi thought he had won it for Napoli with a superb late free kick.
Cagliari's Diego Lopez had pounced in the 56th minute to cancel out Slovak midfielder Marek Hamsik's early opener.
AS Roma continued their return to form after a miserable start to the season with a 3-0 win at Lecce courtesy of first-half goals by Mirko Vucinic and Juan plus captain Francesco Totti's delightful chip four minutes after the break.
Coming on the back of last week's derby victory over Lazio, the win lifts last season's runners-up towards the middle of the standings and boosts the team's morale before Wednesday's visit to CFR Cluj in the Champions League.
Lazio are joint fifth with Fiorentina, who beat visitors Udinese 4-2 on Saturday, after grabbing a 1-1 home draw with Genoa thanks to Ousmane Dabo's powerful strike that slipped through keeper Rubinho's hands 10 minutes from time.
Serie A top scorer Diego Milito had put Genoa in front with his 11th goal of the season in the 69th minute.
The Argentine striker also had a tap-in wrongly disallowed for offside and blasted a penalty over the bar either side of halftime.