Goals from Neymar, Dani Alves and Edinson Cavani paced the Parisian side in an impressive display in Paris, giving Unai Emery's men a perfect start after two matches in the young campaign.
And the hosts wasted little time in finding the opener. Neymar -- playing in his first big Champions League test since joining the club for a world record fee this summer -- cut in from the left, beat a number of defenders and laid off for an overlapping Dani Alves to fire underneath Bayern backup keeper Sven Ulreich with a lashed right-footed shot from an angle.
The assist was the Brazil No. 10's 10th over the past two Champions League campaigns and 17th since the 2013-14 season, which are the most of any player in their respective time spans.
Bayern piled on the pressure in the ensuing minutes -- Thomas Muller and Javi Martinez getting good looks at goal -- but it was PSG who would find the second through Edinson Cavani.
The Uruguay striker, who was at the center of a controversial on-field spat with Neymar last week, made up for a previous wayward effort in the 31st minute, when he sweetly stroked home Kylian Mbappe's layoff with a first-time curler from outside the box.
The goal marked the sixth straight Champions League game in which the in-form Cavani has scored, and gave the French side a comfortable lead heading into the break.
Neymar got his goal just after the hour mark. Mbappe, after brilliantly ghosting inside a helpless David Alaba, slid his cross into the six-yard box, where the Brazilian was first to react after a botched clearance from a defender.
The win gives PSG six points from their opening two games, putting them three points clear of second-placed Bayern and Celtic.
They will visit Anderlecht on Matchday 3.