Hoffenheim's Czech defender Pavel Kaderabek celebrates scoring their third goal against Wolfsburg
Defending champions Bayern Munich will finish the weekend three points clear at the top of the Bundesliga table after close rivals Borussia Dortmund and Wolfsburg both suffered away defeats on Saturday.
Without injured star striker Erling Braut Haaland and club captain Marco Reus, Dortmund had midfielder Mahmoud Dahoud sent off for two first-half yellow cards as their 1-0 defeat at Borussia Moenchengladbach left them fourth in the table.
"Of course, we really missed Erling and Marco today, but we needed a bit more toughness and determination," admitted Dortmund defender Mats Hummels as the visitors played a man down for 50 minutes.
Earlier, Wolfsburg lost 3-1 at Hoffenheim, falling to third and losing second place on goal difference to Bayer Leverkusen, whose 18-year-old Germany international Florian Wirtz sealed a 1-0 win over Mainz to become the youngest player to reach the milestone of 10 Bundesliga goals.
Having lost both Haaland and Reus to injuries in training on Friday, the visitors struggled in front of goal as Moenchengladbach fans whistled Dortmund coach Marco Rose on his return to Borussia Park, where he was in charge for two years before quitting to join their Bundesliga rivals.
The match was decided shortly before half-time when Swiss midfielder Denis Zakaria beat England midfielder Jude Bellingham to the ball and fired the hosts ahead with the game's first clear chance.
Emotions were running high and referee Denis Aytekin dished out eight yellow cards, two of which were shown to Dahoud.
He was booked early for fouling Gladbach captain Lars Stindl, then sent off on 40 minutes for a late tackle on US defender Joe Scally.
Dortmund squandered the chance to grab a late equaliser when Belgium winger Thorgan Hazard headed over in added time.
Haaland and Reus face a race against time to be fit for Tuesday's Champions League game at home to Sporting Lisbon while Saturday's win hauled Gladbach up from the relegation places to 11th.
Wolfsburg took the lead in Sinsheim when winger Ridle Baku fired in a stunning long-range shot from the left flank, but Andrej Kramaric, Christoph Baumgartner and Pavel Kaderabek scored three unanswered goals for Hoffenheim.
"It's a shame we didn't take the points, but Hoffenheim were very efficient - better than us in that regards," said Wolfsburg head coach Mark van Bommel after his first league defeat in charge.
RB Leipzig picked up a much-needed confidence boost before Tuesday's home Champions League game against Brugge with a 6-0 thrashing of Hertha Berlin.
Three defeats in their opening five league games, as well as a 6-3 thrashing at Manchester City in Europe, had piled pressure on Leipzig coach Jesse Marsch.
The American reacted by switching Denmark forward Yussuf Poulsen up front for struggling new striker Andre Silva.
Poulsen linked up with French winger Christopher Nkunku to cause havoc in the Hertha defence.
Nkunku was outstanding with two goals and two assists, while Poulsen, Nordi Mukiele, Emil Forsberg and Amadou Haidara also got on the scoresheet.
Union Berlin are unbeaten in their last 20 home league games after a 1-0 win against Bielefeld in the capital.
Substitute striker Kevin Behrens came off the bench to claim his first Bundesliga goal in only his fourth game for Union.
However, the win was overshadowed by injury to Union defender Timo Baumgartl, who was knocked out during a first-half collision and taken to hospital, where it was confirmed he suffered concussion.
"Timo Baumgartl is doing well. Under the circumstances, that's the most pleasing news," said Union coach Urs Fischer.