Dortmund's star striker Pierre-Emerick Aubameyang scored the all-important goal in the first half to seal a very important win for the Thomas Tuchel's side.
The win pushes Dortmund to the third position in the league and somewhat guarantees them a champions league spot next season.
As for Leipzig, it was a golden opportunity to close the gap with Bayern Munich who were held for a 1-1 draw by Schalke in another important game this week.
Unfortunately, the loss widens the gap to 4 points between Bayern and RB Leipzig.
Here are all the matches from game week 19
Hamburger 1-0 Bayer Leverkusen
Bayern Munich 1-1 Schalke
Hertha 1-0 Ingolstadt
Borussia Monchengladbach 3-0 Freiburg
Hoffenheim 4-0 Mainz
FC Koln 1-0 Wolfsburg
Dortmund 1-0 RB Leipzig
Augsburg 3-2 Werder Bremen
Eintracht 2-0 Darmstadt