Osimhen sinks Fiorentina as Napoli begin Serie A title party
Nigeria striker Osimhen lashed home from the penalty spot in the 74th minute to take his league tally to 23 just a few days after netting the goal which sealed Napoli's third Scudetto with a record-equalling five matches to play.
A party mood has enveloped Naples since Thursday's draw in Udine, and on Sunday afternoon fans let off fireworks and flares in the jammed streets around the stadium named after their icon Diego Maradona on a gorgeously sunny day in southern Italy.
Packed bars and restaurants did a roaring trade with locals and tourists alike decked out in blue as a festive but relaxed mood dominated the city.
Before kick-off supporters put on a display of the Italian flag with the number three in honour of their title wins and hailed their heroes with loud chants of "we are the champions".
But once the match got underway a torpor slowly washed over the ground, not helped by two teams with nothing to play for going through the motions and Napoli creating next to nothing.
Osimhen couldn't even put away a penalty awarded a minute after half-time for Sofyan Amrabat's rugby tackle on Stanislav Lobotka.
However, Serie A's leading scorer was given a chance to redeem himself when Khvicha Kvaratskhelia's weaving dribble towards goal was stopped illegally by Nicolas Gonzalez, and this time he made no mistake.
Flares were lit all around the ground and blue smoke filled the air to hail a win which takes Napoli's massive lead at the top of the table to 17 points over detested rivals Juventus.