(CNN) -- Inter Milan lead Italy's Serie A by seven points as a late Diego Milito penalty gave them a 1-0 win over Fiorentina in the San Siro.
The valuable three points, coupled with a 2-0 defeat at Calgliari for previously second-placed Juventus, left Jose Mourinho's men in charge in their defense of the title.
In the late match, Milan leapfrogged Juve with a 2-0 win at Catania.
Two goals from Klaas Jan Huntelaar in injury time to snatch a late victory after a performance lacking in inspiration.
Inter's win came as a welcome relief after a midweek Champions League defeat to Barcelona which leaves their qualification for the knockout stages in the balance.
The home side had a number of chances to score before Milito struck five minutes time after he was brought down by Gianluca Comotto to earn the spot kick.
Milito had come close to breaking the deadlock on the hour after good work by Samuel Eto'o and Dejan Stankovic, but Alberto Gilardino hit the post for Fiorentina before the only goal of the match.
Eto'o might have added to the tally late on, but wasted a chance when clean through.
Fiorentina came into the match off the back of a Champions League triumph after a 1-0 win over Lyon to eliminate English giants Liverpool, but remain in ninth place in the Italian standings.
Juventus' poor recent run continued as Catania opened the scoring when Daniele Conti took a quick free kick and Nene blasted it past Juventus goalkeeper Gianluigi Buffon.
Substitute Alessandro Matri scored the clincher near the end as the hosts climbed to seventh.
In other matches AS Roma stretched their unbeaten run to five games with a 2-1 win at Atalanta.
Lazio and fellow strugglers Bologna were scoreless at the Stadio Olimpico in Rome while Nicola Amoruso's late penalty earned fifth-placed Parma a 1-1 draw at home to Napoli.