Borussia Dortmund needed a second-half goal by substitute Marco Reus to beat Hoffenheim 1-0.
Reus and top scorer Erling Haaland started on the bench ahead of the trip to Lazio in the Champions League next week, were nowhere near their best and had to wait until late in the first half for their first opportunities.
United States international Giovanni Reyna's effort was saved on the line Thomas Meunier's header bounced off the crossbar.
Dortmund captain Reus and Haaland were brought on in the 64th and instantly breathed life into Dortmund's attack.
They combined perfectly for Reus to tap in the winner 14 minutes from time.