Moise Kean and Pablo Sarabia set out up top alongside Kylian Mbappe in the absence of star figure Neymar Junior, who is expected back after the upcoming international break.
PSG were given a get-out-of-jail free card 15 minutes in when Moses Simon missed an open goal from close-range after a ball from the right-side by Kolo Muani.
That was also the Nigerian international Simon's final contribution, as a knock put his evening to a halt nine minutes thereafter and saw his spot taken by Kader Bamba.
Nantes were handed an opening ten minutes to halftime from Muani who beat Danilo to deliver a curler in a promising position, but the attempt sailed over the bar.
Kays Ruiz-Atil was sent on for his fifth appearance in Ligue 1, with Kean removed at the start of the second half as Nantes showed faith with the same eleven from the first spell.
The 18-year-old Ruiz-Atil played a big part in the opener minutes in from resumption after holding up possession on the left to play in Mbappe, who then found Ander Herrera to convert from close range.
It was 2-0 at the midway stage in the second half when Mbappe comfortably converted from the penalty spot having gone down from Jean-Charles Castelletto's nudge from the back.
Nantes had a chance to get back into the contest from the penalty spot two minutes later after Marcus Coco was sent on the deck by Diallo, but Bamba failed to profit after Keylor Navas' save.
The Ligue 1 leaders added a third goal in the last two minutes through Sarabia who intercepted a back-pass to chip over Alban Lafont, as it finished 3-0 to the defending champions.