Galtier visited his former club with questions surrounding his current tenure after Round of 16 exits in the UEFA Champions League and Coupe de France, as well as two consecutive league defeats.
An eagerness to settle any doubts early on was reflected by his players, but Lionel Messi, Carlos Soler, Nuno Mendes, and Marquinhos all hit shots from range without truly testing Kasper Schmeichel, while Renato Sanches departed injured inside 10 minutes after making back-to-back league starts for the first time this season.
Even so, the visitors provided patient build-up and after Danilo Pereira’s header hit the post, that approach paid off when Messi applied a clinical finish to Mendes’ low cross.
An aimless Sergio Ramos pass that fell to Khephren Thuram threatened to derail Les Parisiens’ progress, although Marquinhos came up with a typically authoritative block on the day he became the third player to reach 400 PSG appearances.
In a reminder that the game was far from won, Gianluigi Donnarumma was then forced into impressive saves by Nicolas Pepe and Terem Moffi before the break.
The visitors endured an uncomfortable start to the second period as Dante’s strike hit the crossbar and post before somehow spinning away from goal - a moment that was followed by Donnarumma tipping Pepe’s sweet strike wide.
For all of the attacking talent within PSG’s ranks, their goalkeeper was proving to be the standout as he sprung across goal to equal Jean-Clair Todibo’s header.
At the other end, Todibo teamed up with Pablo Rosario to halt Kylian Mbappe, with the forward having a quiet game by his lofty standards.
It was Ramos who eventually earned Les Parisiens some breathing space with a header that snuck inside the post, as PSG won their third consecutive away league game to restore their six-point buffer atop the Ligue 1 table.
Meanwhile, Nice’s 14-game unbeaten run across all competitions was brought to an end just two matches short of the club record.
Les Aiglons will need to recover quickly ahead of a trip to Basel as the only French club still maintaining hopes of winning European honours this campaign.