Gonzalo Higuain scored twice as Napoli ran riot against Lazio to clinch their first Serie A win of the season with a resounding 5-0 scoreline on Sunday evening.
The Argentinian forward put Napoli on their way in the 14th minute before Allan doubled the advantage in the 35th minute.
Lorenzo Insigne made it 3-0 shortly after the restart before Higuain added his second before the hour.
Substitute Manolo Gabbiadini struck his team's fifth 11 minutes from time.
Napoli had taken just two points from their opening three games but went into the match at the San Paolo stadium on the back of a morale-boosting 5-0 triumph over Club Brugge in Thursday's Europa League game.
Lazio, who had drawn 1-1 at Dnipro in their Europa League encounter, took their first shot on goal in the 89th minute, Keita's attempt saved by Napoli goalkeeper Pepe Reina.
The hosts went ahead when Higuain found space and drilled a right-footed shot from 20 yards that beat rival goalkeeper Federico Marchetti.
Napoli made it 2-0 shortly after when Insigne set up Allan in the box and he struck a low shot towards the near post out of Marchetti's reach.
Lazio conceded their third in the 47th minute when Marchetti could not hold onto Higuain's right-footed shot and Insigne tapped in the rebound.
In the 59th minute, Higuain surged into the area and hit a right-footed effort towards the far post to beat Marchetti.
Gabbiadini completed the rout with a left-footed strike from 20 yards that found the net.
Lazio substitute Sergej Milinkovic-Savic then saw his stoppage-time header hit the crossbar.
ends