Verona should have gone ahead in the 23rd minute when Davide Faraoni's mishit shot went across the face of the goal but the unmarked Valerio Verre, needing only to force the ball over the line from one metre, contrived to chest it over the crossbar.
Having escaped again minutes later thanks to David Ospina's save from Samuel Di Carmine, Napoli went ahead when Arkadiusz Milik was left totally unmarked at a corner and placed his header into the bottom corner in the 38th minute. It was the Pole's 10th league goal of the season.
On a sweltering evening, Faraoni thought he had levelled in the second half with a header but it was chalked off after a VAR review showed that the ball hit Mattia Zaccagni's arm when he slipped before recovering to provide the cross.
Verona's frustration was complete when Napoli substitute Hirving Lozano, reportedly out of favour with coach Gennaro Gattuso because of his attitude in training, headed in the second at the far post from another corner in the 90th minute.
"We did well, we knew that few teams this year imposed their game here in Verona," said Gattuso. "We imposed ourselves with our quality and with our possession. We need to keep on this path. When you work hard, you reap the rewards."
On Lozano's effort, Gattuso said: "It was a good opportunity for Lozano today and next week it might be Amin Younes. I believe firmly that when you are part of a group, you must all work in the same direction, train at 100%. I hold no grudges."
Napoli, who won the Coppa Italia last week, stayed sixth with 42 points from 27 games after extending their unbeaten run to eight games in all competitions, while Verona dropped four points behind them in eighth.
"I'd like to thank the club that gave the players everything they needed to at home during the lockdown so the lads showed up in great condition," added Gattuso.