Leverkusen won the series in superior style last season.
The team that had never won a Bundesliga title before finished on 90 points, with Stuttgart second on 73.
They also didn't lose a single match in the league.
When the reigning champions kicked off the Bundesliga season 24/25 on Friday evening, they continued on their winning streak.
Away against Mönchengladbach, Leverkusen won 3–2.
The visitors took the lead in the 12th minute when Granit Xhaka thundered the ball into the goal.
About 25 minutes later, 21-year-old Florian Wirtz extended his success in Leverkusen by making it 2–0, which became the halftime score.
In the second half, the home team managed to reduce the score and equalize through Nico Elvedi and Tim Kleindienst, respectively.
But in the absolute final minutes of the 10-minute added time, Leverkusen was awarded a penalty, where Florian Wirtz scored his own penalty to make it 3–2.
The Bundesliga's first round continues on Saturday with matches featuring, among others, Dortmund and RB Leipzig.