With the tie on Friday, Dortmund risks losing their lead in the Bundesliga, earned in a 4-1 opening day route of RB Leipzig, reports Efe news.
Even though Dortmund demonstrated a demolishing effectiveness in their opening match, Lucien Favres team was unable to take advantage of any of the clear chances they found.
The tie was partly the result of Hannover goalkeeper Michael Essers excellent saves, including in the 40th minute, when Marco Reus nearly scored with a right-footed shot from the right of the box.
Just two minutes later, Reus found another chance from the same spot, but his shot bounced off the crossbar.
The goal post saved Hannover once again in the 60th minute, as a header by Maximilian Philipp bounced off the top left corner.
The lack of a goal was about to cost Dortmund dearly in the 78th minute, as Hannover defender Waldemar Anton managed to connect a corner outside the box, though his shot flew just past the left post.