They are one point behind second-placed Nice, still unbeaten in the 2023-24 campaign, and two points off leaders AS Monaco, who travel to Lorient on Sunday.
But the game saw a quick turnaround when Moffi put Nice in front in the 21st minute, netting low inside the near post.
"It was a great Nice team in front of us," substitute Randal Kolo Muani said.
PSG did not lose any of their previous 13 home matches against Nice in all competitions.
Nice, meanwhile, are one of four teams still unbeaten in the top-flight along with Rennes, Olympique de Marseille and Monaco this season.
Persons:
Terem Moffi, Luis Enrique, Ousmane Dembele, Marcin Bulka, Kylian Mbappe, Moffi, Bulka, Mbappe, Dembele, Gaetan Laborde, Gianluigi Donnarumma, Sofiane Diop, Randal Kolo Muani, Anita Kobylinska, Pritha Sarkar
Organizations:
Paris St, PSG, Borussia Dortmund, Champions League, AS Monaco, Nice, Olympique de Marseille, Thomson
Locations:
Ligue, Nice, Lorient, Rennes, Monaco, Gdansk