Napoli have extended their lead at the top of the Serie A table to four points thanks to a 1-0 win at Atalanta BC on Sunday.

Dries Mertens was the matchwinner for the Partenopei, scoring in the 65th minute of the game with a ferocious effort from just inside the area.

The Campanians had lost three of their previous four meetings with Atalanta, including a Coppa Italia quarter-final on January 2, making this fixture a tense proposition for the tabletoppers.

Indeed, neither side could be separated in the first 45 minutes, the hosts playing a tight, pressing game which limited Napoli's forays into the opposition half.

Andrea Masiello was key to Atalanta's defensive stability in the first half as he kept Mertens at bay and also made an overhead kick clearance to stop Jose Callejon going clear on goal.

Napoli improved in the second half and were able to find the breakthrough when a defence-splitting Callejon ball bounced into the path of Mertens, who duly drilled home on the half-volley for his first Serie A goal since October 29.

Marek Hamsik and Marko Rog missed sitters against Atalanta late on, while the former saw an injury-time strike ruled out for offside, but Maurizio Sarri's men still managed to hang on for all three points.

ATALANTA (3-4-1-2): Berisha; Toloi, Caldara, Masiello; Hateboer, Cristante, Freuler, Spinazzola (Gosens 62'); Ilicic (Haas 75'); Cornelius, Gomez

NAPOLI (4-3-3): Reina; Hysaj, Albiol, Koulibaly, Rui; Allan, Jorginho, Zielinski (Rog 86'); Callejon (Maggio 91'), Mertens, Insigne (Hamsik 74')