Dortmund saw midfielder Mahmoud Dahoud sent off for two first-half yellow cards in their 1-0 defeat at Borussia Monchengladbach, leaving them fourth in the standings without injured star scorer Erling Braut Haaland and club captain Marco Reus.
The visitors struggled in front of goal after losing both Haaland and Reus to injury in training on Friday, while Monchengladbach supporters booed Dortmund coach Marco Rose on his return to Borussia Park, where he was in charge for two years before leaving to join their Bundesliga rivals.
Shortly before halftime, Swiss midfielder Denis Zakaria beat England midfielder Jude Bellingham to the ball and put the hosts in front with the game's first clean chance.
Referee Denis Aytekin issued eight yellow cards, two of which were shown to Dahoud, as tempers flared.
He was sent off on 40 minutes after a late challenge on US defender Joe Scally. He was booked early for fouling Gladbach captain Lars Stindl.
Source: transfermarketweb.com