It was actually Matvey Safonov who made the first save of the game, stopping Amadou Koné’s long-distance strike.
PSG started to dominate from there though, as Ousmane Dembele’s shot was well-blocked before Desire Doue struck just over.
A few minutes later, Doue played Bradley Barcola through with an excellent pass, and his fellow countryman made no mistake as he brilliantly found the bottom corner.
The two Frenchmen immediately combined again to double PSG’s lead, as Barcola tapped home Doue’s cross just three minutes later.
Reims were really struggling at this point and Yehvann Diouf kept them in it by tipping Dembele’s shot away before Achraf Hakimi struck over.
Doue and Dembele had further shots off target, before Hakimi effectively put the tie to bed before half-time with a third goal. The flying full-back volleyed home Barcola’s cross at the back post.
Having been involved in all three first-half goals, Barcola was eyeing a hat-trick in the second half, and he almost got it before the hour mark as Diouf palmed his near-post effort away.
Dembele then hit the woodwork twice in the space of a few minutes, as his first shot was saved onto the post by Diouf before his delicate chip clipped the crossbar, although he was offside.
PSG failed to add to their total but will not care as they won their 12th successive match in the competition to lift the trophy, giving them the best possible preparation for the UEFA Champions League (UCL) in a week's time.
Reims must now bounce back the second leg of their relegation playoff against Metz on Thursday with the tie finely balanced at 1-1 after the first leg.
Flashscore Man of the Match: Bradley Barcola (Paris Saint-Germain)