Bayern Munich s French defender Dayot Upamecano (R) is shown a red card by the referee during the German first division Bundesliga football match between Borussia Moenchengladbach v Bayern Munich in Moenchengladbach, western Germany, on February 18, 2023. AFP
Bayern's Upamecano controversially saw a straight red for bringing down surging French compatriot Alassane Plea just outside the box.
Replays showed the contact was minimal but after a short video review the decision stood, making it the second time in the past three Bundesliga games Bayern have been reduced to 10 men.
Bayern goalkeeper Yann Sommer was given a special reception prior to the match, commemorating his eight-and-a-half year stint in Gladbach before moving to Munich to replace the injured Manuel Neuer in January.
Bayern manager Julian Nagelsmann made four changes from his side's 1-0 away win against Paris Saint-Germain in midweek, giving former Manchester United defender Daley Blind his first start.
Gladbach's free kick after the red card came to nothing but the home side were given another chance just five minutes later when Canadian defender Alphonso Davies handled near the corner flag.
Shaping to curl the free kick goalwards, Gladbach midfielder Jonas Hofmann cut the ball back inside to an unmarked Lars Stindl, who struck a low shot through the crowded penalty box and into the goal.
Aware that two sides sit within a win of them in the table, Bayern continued to push.
The 32-time German champions equalised on the counter-attack after 35 minutes, when a lightning fast Davies sped up the sideline and cut the ball back for Eric-Maxim Choupo Moting, who rocketed a one-touch finish into the goal.
Gladbach retook the lead after 55 minutes through Hofmann, who pressed Bayern into a mistake, playing a quick series of passes with Plea before smashing a near-range strike past Sommer.
Gladbach had a chance to make it 3-1 immediately afterwards but Ramy Bensebaini cannoned a long-range shot off the crossbar.
Gladbach's French striker Marcus Thuram sealed the win in the 84th minute when he tapped Hofmann's cross past the outstretched hand of Sommer.
Teenage French striker Mathys Tel scored in injury time to give Bayern home, but the home side held on for a 3-2 victory.
The loss, just Bayern's second of the season in all competitions, cemented Gladbach's status as Munich's bogey side.
The German champions have beaten Gladbach just once in their past seven meetings.
Nkunku back for Leipzig
RB Leipzig won their first match in three games with a 3-0 victory at Wolfsburg, ahead of Wednesday's home Champions League clash with Man City.
With 14 minutes gone, Emil Forsberg punted Leipzig into the lead, taking advantage of Wolfsburg's failure to clear a dangerous ball on the edge of the box.
Leipzig's top scorer Christopher Nkunku, returning from an injury which ruled him out of France's Qatar World Cup campaign, set up his side's second for Konrad Laimer in the 85th minute.
Dominik Szoboszlai scored his side's third in injury time, extending Wolfsburg's winless run to five games.
Elsewhere, goals from Gil Dias, Borna Sosa and Tanguy Coulibaly helped relegation-threatened Stuttgart pick up a valuable three points at home, consigning Cologne to their first loss of 2023 with a 3-0 victory.
Stuttgart climbed out of the bottom three with the win, taking advantage of Bochum's 2-0 home loss against Freiburg.
Freiburg scored either side of halftime through Michael Gregoritsch and Lucas Hoeler to climb into the Champions League placings.
In Saturday's late game, Eintracht Franfurt host Werder Bremen.
On Sunday, second-placed Union Berlin can go first when they host rock-bottom Schalke, ahead of next Sunday's top-of-the-table clash at Bayern.
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