The German was thrilled as his team beat the third division side and set a club record for possession percentage in a competitive match in the process
Goals from Julian Schieber and Jonas Hofmann sent Dortmund into the last 16 of the competition, while the team achieved 84 per cent possession - their highest total ever recorded in a competitive match.
Klopp doubted the third division side would pose a huge threat but was thrilled to see his second-string players shine in the cup clash, with only the team's finishing letting him down.
"An upset was never on the cards," he told the club's official website. "We played a great game even if it only finished 2-0.
"Our finishing could have been a bit better but everything else was perfect. It was fun to watch.
"The lads with little match experience played a fantastic game: Jonas Hofmann, Julian Schieber, and Oli Kirch was the outstanding player. They were really good! It looked fluid despite little playing time."
Dortmund, who sit third in the Bundesliga, can go second behind leaders Bayern Munich if they win Saturday's clash at home to Bayer Leverkusen.