The 18-year-old American netted Dortmund's first goal of the 2017-18 Bundesliga campaign, collecting a pass near the top of the box before rifling a shot into the far corner between two defenders.
Moments later, Marc Bartra followed suit with an equally stunning effort. Pulisic then assisted Pierre-Emerick Aubameyang in the second half to seal the victory.
"I would probably give my goal a B grade," Pulisic said after the game. "Marc's goal was a little bit better, an A for his effort."
He added: "I think I just got the ball at my feet and I kind of just saw an opening, so I just went for it and aimed for the back post and luckily it went in."
With his first goal of the young season, Pulisic became the youngest non-German player to score six goals in the Bundesliga.
It was the second straight match with a goal for Pulisic, who also scored against Bayern Munich in the German Super Cup two weeks ago.