A dominant start from Dortmund was rewarded on nine minutes when Reus tapped into an empty net after Aubameyang had rounded the goalkeeper, before the Gabon international slotted home himself just after half-time.
The Gabon star then popped up again 18 minutes from time to finish off a superb team move on a comfortable afternoon for the visitors.
Victory eases the pressure on coach Jurgen Klopp, who earlier in the week dismissed talk of stepping down following a rotten run that had left the 2013 Champions League finalists propping up the division.
A first win in six Bundesliga games sees Dortmund leapfrog Freiburg into 16th, adding to the relegation worries of Christian Streich's men, who are now level on points with bottom-of-the table Stuttgart.
