The 24-year-old scored from the spot in the 64th minute to give Luciano Spalletti’s side the lead.
It was the Super Eagles striker’s 26th league goal of the season as he finished on top of the top scorers’ chart to become the first African player to win the Paolo Rossi Award.
Osimhen’s substitute Giovanni Simeone added the second for the Naples-based side in the 86th minute to seal a comfortable win for the champions.
Napoli finished the season with an astonishing 90 points, 16 points more than 2nd place team Lazio.
More to come……