Brazil star Neymar had been allowed to travel back to his home country to rest following recent struggles with a groin injury, and while PSG missed his craft, they scraped the win nonetheless.
Angel Di Maria looked PSG's biggest threat in the first half, though his two best strikes did not quite hit the target as the hosts failed to make the most of their superiority.
PSG remained the controlling force after the interval and finally broke the deadlock through Mbappe in the 68th minute, and that proved to be enough as the hosts' first Ligue 1 game since December 5 – due to the 'gilet jaunes' demonstrations – ended with a triumph.
It took less than a minute for PSG to threaten, as Di Maria saw a controlled volley go agonisingly over Ciprian Tatarusanu's crossbar.
But that failed to usher in a period of PSG bombardment, with their next opportunity not presenting itself until the 25th minute, when Julian Draxler shot over from 20 yards after Mbappe's cut-back.
Di Maria went close again a few moments later, his 25-yard strike flying past the right-hand post with Tatarusanu looking beaten.
PSG continued to threaten from distance after the break, with Di Maria – again – and Mbappe shooting just off target in the first 12 minutes.
Draxler thought he opened the scoring after an hour, but VAR proved the ball went out of play in the build-up, despite Marco Verratti's best efforts.
There was no denying Mbappe 22 minutes from time, though, as he turned in – via the crossbar – from close range after Marquinhos flicked on Di Maria's corner.
What does it mean? PSG lacking sharpness
It is fair to say PSG looked a little off the pace on Saturday, and it is easy to understand why, given the only teams they have faced since December 5 were Red Star Belgrade and Orleans. Considering the circumstances and the absence of Neymar, they will surely be happy to get this one out of the way.
Di Maria provides PSG's spark
With Neymar not featuring, Di Maria took on the mantle of PSG's creative hub and he was certainly lively, seeing several shots go close. He was unable to get a deserved goal, but there is no doubt about the quality he showed.
Cavani blends into the background
Perhaps the service to him was lacking, but Edinson Cavani did little to make any openings for himself and rarely featured in build-up play before being hooked towards the end.
Key Opta Facts
- PSG have won their last 14 games against Nantes in Ligue 1, and become the first ever top-flight team to win 14 consecutive games against the same opponent.
- Nantes have failed to score in eight of their last 10 away games against PSG in Ligue 1 (2 goals).
- Thomas Tuchel's side have picked up 47 points after 17 games in Ligue 1, the highest tally in the history of the top-flight at this stage.
- PSG are the only team to have scored in all of their Ligue 1 games this season (17/17).
- Mbappé’s goal in the 68th minute was PSG's first shot on target.
- The 20-year-old has scored 13 goals in Ligue 1 this season, only Lionel Messi (15) has scored more in the top 5 leagues.
After the winter break, PSG have games against Pontivy and Guingamp in the Coupe de France and Coupe de la Ligue, respectively, before then returning to Ligue 1 action on January 11 at Amiens. Nantes will host Chateauroux in the Coupe de France, then Montpellier in the league four days later on January 8.