Inter Milan's run of seven successive Serie A wins came to an abrupt end on Sunday as they fell to a 1-0 defeat by relegation strugglers Lecce.
Inter's loss leaves them nine points adrift of leaders Juventus, who beat Udinese 2-1 on Saturday, while city rivals AC Milan can stay a point behind the leaders should they beat Calgiari later on Sunday.
There was also a surprise loss for Napoli, who had ended Inter's defence of their Italian Cup trophy on Wednesday, as they went down 3-2 at mid-table Genoa and now trail Juventus by 15 points.
Uruguayan Guillermo Giaccomazzi struck for Lecce to give them their first home win of the season - they had previously taken just two points from the 27 available at home - while their 'keeper Massimiliano Benassi was in superlative form denying Inter on several occasions.
Lecce's win took them to three points from safety, fourth from bottom Siena having lost 2-1 earlier on Sunday to Fiorentina.
Napoli's loss was even more of a shock because only last month they had walloped Genoa 6-1, but this time round they found themselves trailing 3-0.
A double from Argentinian Rodrigo Palacio, taking him to 11 for the season, and a first goal in their colours from veteran Italian World Cup winner Alberto Gilardino, who joined in the transfer window from Fiorentina set Napoli an almost impossible task.
However, they made a game of it but only in the last 10 minutes as Uruguayan Edinson Cavani and Argentinian Ezequiel Lavezzi struck in the 80th and 82nd minutes respectively.
Lazio kept in touch with the battle for Champions League places with a 3-0 win over Chievo, two late goals from veteran German international striker Miroslav Klose sealing the victory.
Their city rivals AS Roma lost ground on them after being held 1-1 by Bologna despite a superb goal from a freekick by Bosnian international Miralem Pjanic.