Reus, who joined Dortmund from Gladbach just over a decade ago, scored two goals and added three assists, but he declined to take a penalty his team were awarded in additional time, which Emre Can stepped up and converted to complete the rout.
Reus scored the game’s first goal in the 26th minute, pouncing on a rebound after Switzerland goalkeeper Yann Sommer parried a Donyell Malen attempt.
Six minutes later, Reus returned the favor, playing a one-two with Dutchman Malen, who sent a shot past Sommer to increase Dortmund’s lead.
Dortmund put the game out of reach when Reus set up Marius Wolf for a 70th-minute goal, just two minutes after coming off the bench.
Four minutes later, Youssoufa-Moukoko, another replacement, scored Dortmund’s fourth goal, giving the captain his third assist of the game.
After a long pass from defender Mats Hummels, Reus got back among the goals, before Can finished Gladbach’s humiliation from the penalty spot after Wolf was felled in the box.
