Dries Mertens and Matteo Politano’s goals were the difference in a routine win for Napoli, who took the three points and moved up into sixth place, equal on 43 points with Lazio.
The home side started the game with real intent dominating possession and keeping Benevento locked in their own half.
Napoli broke the deadlock when Dries Mertens guided in a Faouzi Ghoulam shot that kindly found its way to Mertens just outside the six-yard box for a simple tap-in. The goal marked a celebratory return to the Partenopei XI for the Belgian, who was making his first Serie A start since mid-December.
Benevento reacted well though and created their first significant chance with Fabio Depaoli forcing Alex Meret to produce a solid save.
After the interval, the game proceeded as a more balanced affair with Benevento being more adventurous.
Despite a more positive approach, Filippo Inzaghi’s side conceded a second when a delightful Lorenzo Insigne cross was fumbled over the line fortunately by Matteo Politano to give his side a well-deserved two-goal cushion.
Kalidou Koulibaly was sent off late on for a clumsy foul that led to a second yellow card leaving his team with ten men.
Napoli saw the game out in a controlled manner even with a man less to see off Benevento.