Inter Milan suffered their first defeat in eight Serie A matches on Sunday, going down 1-0 away to Lecce, while AC Milan kept the pressure on leaders Juventus with a thrashing of Cagliari.
Guillermo Giacomazzi stunned visitors Inter by firing home just before the break at the Stadio Via del Mare.
Although Inter dominated the second half and had two goals disallowed for offside, they were unable to find a way past Lecce goalkeeper Massimiliano Benassi, who produced a string of sensational saves over the course of the 90 minutes.
Elsewhere, AC Milan earned a valuable three points with a 3-0 win over Cagliari at San Siro.
Zlatan Ibrahimovic opened the scoring with a well taken free kick in the 32nd minute and then assisted Antonio Nocerino for his side’s second with a deftly chested knock down.
Massimo Ambrosini then wrapped up the points in 15 minutes remaining.
The win means the gap between and leaders Juventus remains at a point at the top of Serie A
A Rodrigo Palacio brace and Alberto Gilardino's goal helped Genoa defeat Napoli 3-2 at home.
After falling 3-0 behind at the Stadio Comunale Luigi Ferraris, Edinson Cavani and Ezequiel Lavezzi struck in the final 11 minutes to give the visitors hope, but they proved unable to force what would have been a dramatic equaliser.
Igor Budan netted twice as Palermo downed Novara 2-0 at home.
Miroslav Klose bagged a double of his own in Lazio's 3-0 win away to Chievo Verona, with Hernanes claiming the other goal.
Marco Rossi's 76th-minute penalty proved to be the winner for Cesena in their match at home to 10-man Atalanta.
Roma needed a Miralem Pjanic equaliser to take a point from the visit of Bologna to the Italian capital.
Finally, Stevan Jovetic and Cesare Natali were on target as Fiorentina saw off Siena 2-1, with Emanuele Calaio's 89th-minute penalty a consolation for the beaten visitors.