The Argentine settled a frantic encounter after an own goal from former Chelsea defender Alex had cancelled out Edinson Cavani's first-half opener on Sunday.
Laurent Blanc again named Cavani and Zlatan Ibrahimovic together up front, with the only change from the 1-1 draw with Ajaccio coming in defense, as Gregory van der Wiel replaced Christophe Jallet at right back.
Newly-promoted Nantes recalled midfielder Jordan Veretout to the side as he returned from suspension following his dismissal in the win over Bastia two weeks ago.
PSG made a strong start to proceedings and came close to silencing the vociferous crowd at the Stade de la Beaujoire, Ibrahimovic denied by Remy Riou from close range after he had latched on to a lofted through ball from Thiago Motta.
Cavani fired a warning shot just after the 20-minute mark as he lashed a volley wide from range, and just a few minutes later the Uruguayan opened the scoring.
Ibrahimovic - so often the talisman for PSG - turned creator, the Swede splitting the Nantes defense with an excellent through-ball for Cavani to slot home with a composed finish after 24 minutes.
The gulf in class between the two sides was evident, with Nantes struggling to impose itself on the contest as PSG dictated play in the midfield.
The visitors did sit back somewhat in the closing stages of the first half, though, and that allowed Nantes to fashion its first real opening of the game.
Vincent Bessat looked to be through on goal but a superb covering tackle from Maxwell denied him the chance to shoot.
Nantes almost tied things up from the resulting corner, Gabriel Cichero forcing Salvatore Sirigu into a superb save with a spectacular scissor kick.
The hosts carried that momentum into the second half, however, and a mere seven minutes after the interval they were level.
Alex deflected Veretout's free kick into his own net after Papy Djilobodji had met the delivery at the far post.
Nantes' equalizer opened up the game at both ends, but it was Michel Der Zakarian's men who went closest to taking the lead as Sirigu produced a remarkable save to tip Alejandro Bedoya's header over the bar.
PSG responded well, Lavezzi testing Riou from a tight angle after good work down the left-hand side, before Ibrahimovic fired over from point-blank range as Van der Wiel exploited a gap in the Nantes' backline.
The visitors' onslaught eventually proved too much for Nantes, and it was Lavezzi who restored PSG's lead.
The Argentine made no mistake with an easy opportunity, slamming home after substitute Lucas Moura's was effort cleared off the line following a passage of play that had seen Cavani fail to control a square pass from Blaise Matuidi, who had been put through by Ibrahimovic.
Nantes pressed to try to find a leveler, but in truth it was PSG which should have added to its lead as Ibrahimovic fired wide late on.