Third-division side Arminia Bielefeld pulled off a historic upset on Tuesday, rallying to defeat defending champion Bayer Leverkusen 2-1 and secure their first-ever German Cup final berth.

Leverkusen appeared in control early when Jonathan Tah volleyed home Amine Adli's 17th-minute corner at the back post. Bielefeld, however, refused to buckle. Marius Worl pounced on a loose ball just three minutes later, slotting calmly past goalkeeper Lukas Hradecky to level the match.

The underdogs struck again on the stroke of halftime. Louis Oppie's whipped free kick found Maximilian Grosser at the far post, whose clinical volley sent the home crowd into raptures.

Leverkusen introduced forwards Victor Boniface and Patrik Schick after the break but struggled to break down a resolute Bielefeld defense. Goalkeeper Jonas Kersken preserved the lead with a fingertip save to deny Boniface's header, while Schick's late effort agonizingly grazed the post.

"We are simply proud of the team," said Arminia Bielefeld head coach Mitch Kniat. "We made our dream come true by reaching the final in Berlin. We defended with passion, and it was great to take the lead just before the break. All in all, it's a well-deserved win."

Leverkusen midfielder Robert Andrich conceded: "It is very hard to say what exactly went wrong today. We have to be honest - Bielefeld deserved to be in the final. We just couldn't find a way through up front."

Bielefeld, having eliminated Union Berlin, Freiburg, and Werder Bremen, will face either Stuttgart or RB Leipzig in the final.