In the 72nd minute, the Nigerian striker missed his penalty after Riccardo Calafiori, a replacement, was struck by a deflected cross from Khvicha Kvaratskhelia.
The champions are mired in seventh position in the rankings and are seven points behind league leaders Inter Milan following a run of two victories, one loss, and two draws. With six points, Bologna is in 11th place.
Rudi Garcia, the manager of Napoli, made an effort to remain upbeat despite the outcome.
He told newsmen, “The performance was good, especially in the first half. The result is the negative element.”
“We had some tactics that worked but are not entirely happy because there is no victory.”