If the French champions needed a gentle return to action they got their wish with struggling Dijon offering little once Marquinhos gave Thomas Tuchel's side a seventh-minute lead.
Kylian Mbappe doubled PSG's advantage shortly before halftime after good work by Angel di Maria.
Di Maria's exquisite free kick made it 3-0 five minutes after the interval and Mbappe was then denied by the woodwork before Eric Maxim Choupo-Moting rounded off a comfortable night's work with PSG's fourth goal in stoppage time.
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Tuchel praised his side's reaction after last week's meltdown against United when they allowed a 2-0 first-leg victory to be overturned by injury-hit opposition.
"The team reacted well, it was a first step," he said.
"The challenge was to show we react like champions. It's been a tough few days, but to respond, to show we are a united team with a special spirit, was an obligation."
PSG have 74 points from 27 games with second-placed Lille on 57 from 28.
(Reporting by Martyn Herman; Editing by Toby Davis and Ken Ferris)
