However the hosts were level in the 13th minute thanks to a impressive low curling effort from Mounir Chouiar, which squeezed past Kaylor Navas.
While the away side were far from full strength, with Angel Di Maria and Mauro Icardi on the bench and Neymar not even in the squad, Thomas Tuchel’s team did include Kylian Mbappe and Edinson Cavani, who was making his first start in over a month after nearly moving to Atletico Madrid in January.
The Uruguayan was left waiting for his 200th goal for the club in the 21st minute when he turned home Thomas Meunier’s cross, only for the strike to be ruled out for handball by the Belgian after a VAR check.
“It’s not that bad because he can score his 200th goal on Saturday (against Amiens) or Tuesday (against Borussia Dortmund). I can feel he’s there,” said Tuchel.
On the match, he added: “I’m happy because we deserved the victory. It’s a huge performance.”
Mbappe put PSG ahead a minute before the break, punishing Jhonder Cadiz’s miss when clean through seconds before by clinically slotting home a similar chance.
Thiago Silva added a third four minutes after the break with a header from a corner before Pablo Sarabia ended Dijon’s resistance by pushing home his 11th of the season on the rebound.
Senou Coulibaly watched on in horror with five minutes left when Mbappe’s cross looped off his thigh over helpless stopper Runar Alex Runarsson, before Sarabia tapped home his second in stoppage time from another Mbappe centre.
Later, Lyon coach Rudi Garcia knocked his former side Marseille out as Houssem Aouar scored an 81st-minute winner.
The winning goal came 10 minutes after Lyon’s Moussa Dembele had a penalty – awarded when Hiroki Sakai handled a shot from Karl Toko Ekambi – saved by Yohan Pele in the Marseille goal.
It was the third time this season that Dembele had missed from the spot for Lyon.
On Thursday, fourth division side Epinal – last 16 conquerors of Lille – will look to continue their stunning cup run going when they host Saint-Etienne.
They will try to succeed where fellow fourth-tier outfit Belfort failed following their 3-0 defeat to holder Rennes on Tuesday.