Maurizio Sarri’s men gave a spirited performance to turnaround a goal deficit as they continue the chase for their first Italian Serie A title since 1990.
Mariusz Stepinski fired Chievo ahead with his 73rd minute goal but Arkadiusz Milik drew the hosts levelled to start the dramatic comeback in the 89th minute.
At the death, Diawara curled a right-footed shot to the back of the net to grab the crucial three points for the Naples outfit.
The victory means Napoli remain within four points of leaders Juventus.
"I did not imagine I’d score my debut goal like that, but the ball came to me and I went for it. After the goal, all my teammates, the coach and the staff gave me a pat on the back. I’ll bring a cake to the locker room as thanks!," Diawara told Mediaset Premium.
“We were so unlucky in the first half, had so many chances and couldn’t convert them. We are working well and hope the forwards can return to scoring goals soon.
“I work hard in training, put myself at the disposal of the coach and I'm very grateful every time I am given the opportunity to play and show what I can do.
“There’s a long way to go and we have to win every game. We will fight to the bitter end on every ball, from the first minute to the last, and always try to win.”
The former Bologna player dedicated his maiden Serie A goal to his late mother.
“It was a very important goal for the team and I am also happy for my debut Serie A goal,” he continued.
“I dedicate this goal to my mother, who died a year before I came to Italy, so she didn’t get to see me play in Serie A.”