Raul Albiol marked his 200th appearance for Napoli with a 72nd-minute winner against Genoa which breathed new life into the Serie A title race.
Albiol's glancing header proved enough to see off Genoa 1-0 at the Stadio San Paolo and reduce the gap on leaders Juventus to just two points.
The title favourites had surprisingly dropped two points in a draw with struggling SPAL on Saturday, but Napoli were forced to work hard to take full advantage.
Despite coming into the game on the back of two straight losses, Genoa started well with Darko Lazovic stretching the home defence in the early stages before Dries Mertens sent Napoli's first chance just wide.
The home side lost striker Marek Hamsik to injury after just 20 minutes and it was the visitors who continued to make a strong impression with Nicolas Spolli coming agonisingly close to heading them into the lead.
Brazilian Allan missed a golden chance for Napoli at the other end but as the home side began to take control, Lorenzo Insigne headed against the bar from a corner.
Mertens also hit the woodwork early in the second half but Genoa refused to buckle and Adel Taarabt came close on the end of a fleeting counter-attack.
With the frustration starting to show, Albiol chose a timely moment to score a rare goal, rising above the Genoa defence to head home a Jose Callejon corner at the near post.
Napoli almost made the game safe late on when a clever through-ball from Arkadiusz Milik allowed Insigne to fire past keeper Mattia Perin, only for Davide Biraschi to get back and clear off the line.