Marco Reus was once again the hero in extra time for Borussia Dortmund.

Reus scored a 121st-minute penalty to give Dortmund a 3-2 win over Union Berlin in the second round of the German Cup on Wednesday.

The Dortmund captain had also scored in the 120th minute of the side's 2-1 win over Greuther Fuerth in the first round.

Dortmund, which allowed Hertha Berlin to snatch a late 2-2 draw in the Bundesliga on Saturday, again let a team from the capital off the hook when Sebastian Polter headed an equalizer for second-division Union.

Simon Hedlund should have put the visitors ahead in extra time, and Union was to rue the miss as Dortmund finished strongly.

American midfielder Christian Pulisic, who scored one and set up the other in normal time for Dortmund, was awarded the penalty when he was pulled back by Union defender Marvin Friedrich, who was sent off with his second yellow card.

Reus, who had come on in the 78th, stepped up to guarantee there would be no penalty shoot-out.

It ensured Dortmund stayed unbeaten in 14 games under new coach Lucien Favre.

"Congratulations to Union Berlin and Urs," Favre said, referring to counterpart Urs Fischer. "It was very difficult to play against this team and to destabilize them."

Elsewhere, Bayer Leverkusen routed Bundesliga rival Borussia Moenchengladbach 5-0 away, following up on its 6-2 win at Werder Bremen in the league to ease the pressure on coach Heiko Herrlich after an indifferent start to the season.

Second-division Holstein Kiel upset Freiburg 2-1, despite the visitors scoring after 42 seconds.

Leipzig defeated Hoffenheim 2-0, and MSV Duisburg won 3-0 at second-division rival Arminia Bielefeld.

Schalke progressed 6-5 on penalties at second-division Cologne and Nuremberg beat second-tier rival Hansa Rostock 4-2 away on penalties.

Werder Bremen routed fourth-division side Weiche Flensburg 5-1 with 40-year-old Claudio Pizarro opening the scoring for the visitors.