Bahebeck, a goalscorer in all three of PSG's previous friendlies, continued his impressive form in the build up to the new campaign, as he netted the opener at the Stade de la Mediterranee in Beziers before Marquinhos wrapped up the win.
A late goal from teenager Franck Honorat gave Nice something to take from the game, but Laurent Blanc's side had already done enough by that stage.
Following wins for PSG over Hartberg and Videoton before losing to Red Bull Leipzig during pre-season, Nice promised to provide sterner opposition for the Ligue 1 champions.
However, Blanc's side started brightly and forged ahead in the third minute when Bahebeck slotted in at the far post after being cleverly played in by last season's Ligue 1 top scorer, Zlatan Ibrahimovic.
But for all their endeavour, Claude Puel's side could not find an equaliser.
