Napoli remained top of the Italian Serie A after a hard fought 1-0 win over Atalanta.The hosts put up a plucky defence, with Masiello hooking a heroic goal line clearance to stop Callejon from scoring in the first half. However, there was little they could do to stop the only goal of the game. Callejon lofted a perfect pass for Mertens, who calmly volleyed in a powerful strike to seal the win.