Third-division Saarbruecken continued their giant-killing German Cup run on Tuesday, Kai Bruenker scoring in stoppage time as they beat Borussia Moenchengladbach 2-1 to reach the semi-finals.

Having already eliminated Bayern Munich and Eintracht Frankfurt from the German Cup, Saarbruecken hosted three-time winners Gladbach, one of only two top-division teams left in the competition.

Gladbach's Robin Hack, who came on and scored two goals in three minutes in Saturday's 3-3 Bundesliga derby draw with Cologne, tapped in a Franck Honorat pass to open the scoring after eight minutes.

The hosts hit back immediately, Amine Naifi blasting a rocket into the top corner to level the scores.

The match, which was postponed from February due to heavy rain, was played in a teeming downfall on a sodden pitch and looked to be headed for extra time when Bruenker scored on the counter in the final minute of stoppage time.

"That was a fight," a fired-up Bruenker told Germany's ZDF network, with fans chanting "Berlin, we're coming to Berlin" in the background.

The final will be played in Berlin on May 25.

"We just ran and ran after the ball -- it's completely insane. We've got some mentality monsters in our ranks."

Saarbruecken will face two-time winners Kaiserslautern in the semi-finals.

The other semi-final features Bundesliga leaders Bayer Leverkusen -- the only top-division team left in the competition -- and neighbours Fortuna Duesseldorf, who have lifted the German Cup twice.