Marek Hamsik's 72nd-minute goal was enough for Napoli to secure a 1-0 win at Cagliari on Monday, moving the club into second place in Serie A.
The win, coupled with a 1-0 defeat by Juventus against AC Milan on Sunday, leaves Napoli two points back of Juve, while Cagliari remains in the bottom half having failed to win any of its last four matches.
Lorenzo Insigne struck the post for Napoli in the first half, but it was Cagliari that posed a more consistent threat.
Paolo Cannavaro nearly diverted the ball into his own net from a Cagliari cross, but the ball hit the top of the crossbar, while Napoli slowly began to test goalkeeper Michael Agazzi.
But the decisive move came in the final 20 minutes with Cagliari defender Albin Ekdal redirecting a pass into the path of Hamsik, who pounced on the loose ball and curled a shot inside the far post.
Parma 1, Inter Milan 0
Parma, Italy - Inter Milan's struggles continued on Monday as the club failed to close the gap on Juventus after sustaining a 1-0 defeat at Parma.
After a run of seven successive victories, Inter has claimed just one point form its last three matches, leaving the club four points adrift of Juventus at the top of the league.
Inter defender Walter Samuel nearly handed Parma the opening goal when he redirected a cross onto his own goal, forcing goalkeeper Samir Handanovic into a good reaction stop.
Esteban Cambiasso almost put Inter ahead before halftime with a close-range header that was well saved by goalkeeper Antonio Mirante, keeping the game scoreless.
But Parma produced one moment of individual class to snatch the win as Nicola Sansone collected the ball and split a pair of Inter defenders before firing a shot past Handanovic.