Napoli have extended their unbeaten Serie A run to five games thanks to Dries Mertens's double against Sampdoria today.
Playing their first game since the winter break, Rafael Benitez's side couldn't break the deadlock in the opening 45 minutes as Mertens and Gonzalo Higuain were both denied by Sampdoria keeper Angelo da Costa Junior.
Nenad Krsticic wasted the visitors' best chance of the first half as he overran the ball after rounding Napoli keeper Rafael Cabral.
The home side went in front in the 52nd minute when Higuain crossed from the right and Mertens tucked home at the near post.
The Belgian had his second nine minutes later when he curled home a free kick into the bottom corner.
In between the two goals Sampdoria almost equalised when Manolo Gabbiadini's shot ricocheted off the underside of the bar but failed to bounce over the goalline.
The visitors struck the woodwork again 13 minutes from time when Nicola Pozzi's shot unluckily hit both posts before drifting away from goal.
Three points for Napoli see them pull clear in third place and move to within two points of Roma in second, while Sampdoria drop a place to 14th.