Jupp Heynckes suffered a first defeat of his fourth spell in charge of Bayern Munich with a 2-1 loss to his former side Borussia Monchengladbach.
Gladbach took control with two-goal burst in a five-minute spell just before half time. Thorgan Hazard put the home side ahead from the penalty spot on 39 minutes, before German international Matthias Ginter doubled the lead with a close range tap in a minute before the break.
Arturo Vidal reduced the arrears with 16 minutes remaining but it proved a mere consolations as Heynckes tasted defeat for the first time in 31 Bundesliga games, since he oversaw a loss to Bayer Leverkusen in December 2012 during their Treble-winning season.
The depleted reigning champions also lost Juan Bernat and James Rodriguez to injury before half-time as nearest challengers RB Leipzig closed to within three points of Bayern at the top following a comfortable 2-0 win over struggling Werder Bremen.
Injury-ravaged Bayern doggedly fought back from a 2-0 deficit at the break and could easily have grabbed a draw.
Slipped to a 20th top-flight defeat on their 50th trip for the only true Klassiker -- Bayern have lost more games in Monchengladbach than against any other Bundesliga opponent. Bernat broke down again for an already decimated Bayern who will hope James has just a minor concussion, having lost Arjen Robben and Thiago earlier in the week.
Manager rating out of 10
6 -- After nine consecutive wins in all competitions, Heynckes tasted defeat for the first time in his fourth term on an emotional return to the club where he won four Bundesliga titles as a feared striker, becoming the Bundesliga's youngest ever coach at the age of 34 in 1979 before switching eight years later for his first Bayern tenure.
Player ratings (1-10; 10 = best. Players introduced after 70 minutes get no rating)
GK Sven Ulreich, 6 -- Could not do anything about the goals, apart from protest more vehemently for offside or against the handball decision.
DF Juan Bernat, 5 -- Far from effective when burdened with extra defensive work, pulling up with injury immediately after Bayern fell behind.
DF Mats Hummels, 6 -- Always a threat in Gladbach's box but Bayern had left themselves too much to do after a timid first half display.
DF Niklas Sule, 5 -- Sluggish alongside Hummels in central defence, giving away the penalty for handball in the box -- his first defeat in a Bayern shirt in 10 Bundesliga appearances since joining from Hoffenheim.
DF Joshua Kimmich, 6 -- Rampaged down the right flank in the second half as Bayern tried in vain to fight back after a less than impressive opening 45 minutes.
MF Javi Martinez, 6 -- Assumed the captain's armband in the injury enforced absence of Manuel Neuer and Co. but not at his best, especially in a lethargic first half.
MF Sebastian Rudy, 5 -- Tested Yann Sommer with a rasping drive just before the half hour but that was the sum of Rudy's attacking intent.
MF Corentin Tolisso, 5 -- Bayern's record signing glanced a powerful header narrowly over after 15 minutes but struggled to impose himself on the game, picking up a yellow card for a hefty challenge on the goalscorer Ginter.
MF Arturo Vidal, 6 -- Scored for the second consecutive week, driving home his third league goal of the season through a crowd of bodies from the edge of the box. Vidal was to the fore as Bayern bravely battled back, but the damage had already been done.
MF James Rodriguez, 6 -- The Colombia international was among Bayern's brightest in the opening period, but was forced to stay in the changing rooms following a nasty clash of heads with Tony Jantschke just after the half hour mark. According to Heynckes, James did not know what the score was after suffering a mild concussion.
FW Robert Lewandowski, 5 -- Largely anonymous for long periods other than hitting the post with a magnificent back heel just before the break. Has never found the net in six games against Gladbach in a Bayern shirt, as the Foals join HSV and Hoffenheim as the only sides Lewandowski has failed to score against in the league this season.
MF Kingsley Coman, 6 -- Replaced Bernat on the stroke of half-time with his side trailing and toiled industriously to repair the damage, hitting the post on 66 minutes with a fierce drive.
DF Marco Friedl, 6 -- Cannot be faulted on his league debut as Bayern were already two goals down by the time he entered the fray. Not tested defensively as Gladbach hardly ventured outside their own half in the second period.
FW Kwasi Okyere Wriedt, 6 -- Signed from Osnabruck in the summer, the 23-year-old enjoyed a league debut -- pushed up front for the last 22 minutes allowing Lewandowski more space to sniff a goal. Only last month, the German with Ghanaian roots had been starring in Bayern's reserve side that won the fourth-tier Munich derby.