Inter Milan have lost ground on Serie A leaders Juventus after suffering a surprise defeat at Parma tonight.
Nicola Sansone scored the only goal of the game as Parma extended their unbeaten home record this season to seven matches.
Experienced defender Walter Samuel nearly gifted the hosts an early lead when he inadvertently diverted a cross towards his own goal, but Inter keeper Samir Handanovic was alert to spare the Argentine's blushes.
From then on most of the first-half chances fell at the right end from Inter's point of view as both Esteban Cambiasso and Fredy Guarin came close to an opener.
Former Juve striker Amauri saw a header saved by Handanovic as Parma came back into the game as half-time approached, but Inter regained control of proceedings after the break.
Diego Milito's tame effort was held comfortably by Antonio Mirante, before Guarin forced the Parma stopper into a smart save with a drive from the edge of the box.
After 75 minutes of goalless action, Sansone broke the stalemate when he dribbled past Guarin before shooting past Handanovic from 20 yards.
Inter are now four points adrift of Juventus, while the result sees Parma climb to seventh in the Serie A table.