However, their struggles away from home continued in Lisbon, as Benfica dominated the early stages and should have opened the scoring inside the opening quarter-hour.
A quick counter-attack found Fredrik Aursnes, only for him to be denied by Vanja Milinkovic-Savic, before Franjo Ivanovic curled a shot agonisingly wide. Aursnes was not at his best in front of goal and had another fantastic opportunity when Milinkovic-Savic played the ball into his feet, but, with the goal at his mercy, he dragged his shot wide.
Benfica continued to probe for the opener, and it arrived just before the midway point of the first half when a lofted ball into the box was nodded down by Ivanovic before Richard Rios got a vital touch to poke home.
It took until the half-hour mark for the Partenopei to make a foray forward, yet Giovanni Di Lorenzo could only head wide after being picked out at the back post by Noa Lang.
The hosts continued to look the better side as half-time approached, and Nicolas Otamendi had the chance to double their lead going into the break. However, his wild volley from inside the area went high and wide.
Conte was clearly concerned by his side’s first-half performance, introducing Leonardo Spinazzola and Matteo Politano at the interval. Those changes had little effect, however, as Benfica doubled their lead within five minutes of the restart.
The goal came after the hosts dealt with a Napoli corner when Alessandro Buongiorno headed into the hands of Anatoliy Trubin. The goalkeeper then sent the ball up the pitch, and a spectacular team move culminated with Ríos sliding the ball to the front post, where Leandro Barreiro finished with a sublime backheel flick.
Napoli never looked like pulling a goal back and took until the 71st minute to test Trubin, when David Neres cut inside from the right flank and unleashed a powerful effort from the edge of the box that the Ukrainian stopper palmed over the bar.
The home side almost put the game out of sight late on, but Vangelis Pavlidis had an effort tipped around the post before Milinkovic-Savic once again denied the Greek.
In the end, Benfica saw out the remaining minutes with ease, claiming just their second win of the UCL league Phase. Nevertheless, the Portuguese outfit remain a point away from the play-off places and their opponents, who sit in 23rd place.
Flashscore Man of the Match: Richard Rios (Benfica)