The Napoli, who have been confirmed as Italian vice-champion of football, finished today with a 3-2 defeat at Bologna on Matchday 38.
Paraguay forward Federico Santander struck in the 43rd and 88th minutes and his second goal was decisive after the Neapolitans drew 1-1 with Algerian Ghoulam (57) and Belgian Dries Mertens (77).
The Swiss midfielder Blerim Džemaili (45) had made it 2-0 for the hosts.
Napoli finished the season with 79 points, 11 fewer than champions Juventus, who visit Sampdoria on Sunday. Bologna is provisionally in 10th.
Frosinone and Chievo, penultimate and last, tied for zero.
On Sunday, the European places are decided and the third team to descend, in this case with Genoa in a more precarious situation.
At the top of the standings, Atalanta and Inter, with 66 points, are in Champions League places and play at home with Sassuolo and Empoli, respectively, while AC Milan, with 65 points, visit SPAL.
Roma have 63 points and Parma, and Torino, with 60, play at home with Lazio.