Joachim Low's side went into the game needing to match or better Sweden's result against Mexico, but they failed to break down Korea's dogged resistance and were undone at the last as Kim Young-gwon and Son Heung-min netted, while the Scandinavians romped to a 3-0 victory.
If World Cup-winning head coach Low thought his problems were behind him after a superb second half in Germany's 2-1 win over Sweden in their second Group F game, he was wrong, and the inclusion of Mesut Ozil in the front four did little to inspire his turgid team.
Korea, with nothing to play for but pride, gave everything they had in hot conditions in Kazan and got their reward in stoppage time when Kim struck from close range and had an offside decision overturned by VAR before Son raced clear of the German defence and rolled the ball into an empty net.
Whether Germany's failure spells the end of Low's glorious era in charge of the national team remains to be seen, but he will certainly face questions as to why his side were so desperately lacking in cohesion in Russia and urgency when the stakes were so high.
3 - Germany are the third successive World Cup reigning champions to be eliminated in the group stages after Spain in 2014 and Italy in 2010. Humbled. #GER #KOR#KORGER #WorldCup pic.twitter.com/CMMjn8jgBF
— OptaJoe (@OptaJoe) June 27, 2018
Thomas Muller was absent from Germany's starting line-up for the first time in a World Cup game since their semi-final defeat to Spain in 2010, with Schalke midfielder Leon Goretzka taking his place alongside Ozil.
Korea matched Germany's physicality as strong challenges punctuated the first 10 minutes and they almost took the lead when Manuel Neuer spilled Jung Woo-young's swerving 25-yard free-kick, but the Bayern Munich goalkeeper managed to punch the ball out for a corner before anyone could pounce on the rebound.
Despite goal difference being potentially decisive for Germany, the early chances continued to fall to Korea and Son screwed a shot wide from the edge of the penalty area before Marco Reus rattled one towards goal at the other end only to see it blocked.
Timo Werner looped a shot over the crossbar via a deflection off Kim and the ensuing corner presented a chance to Mats Hummels, but he could not get his shot away as Korea threw bodies behind the ball.
Just as they did against Sweden, Germany emerged for the second half looking fired up and Goretzka drew a brilliant one-handed save from Cho Hyun-woo with a free header from the middle of the penalty area, the Korean goalkeeper diving to his right and pushing the ball away at full stretch.
Werner flashed a superbly executed volley narrowly wide moments later as news that Sweden were ahead reached the stadium, and Germany piled forward in search of a goal they urgently required.
Toni Kroos had a shot blocked from great position inside the box, but Korea continued to be effective on the counter-attack and one sweeping move culminated in Son lifting a shot over the crossbar from 20 yards.
Substitute Mario Gomez headed straight at Cho with a free header after 67 minutes as Germany's play became increasingly anxious, and, after their last clear chance was headed over at point blank range by Mats Hummels, they fell apart.
— FIFA World Cup (@FIFAWorldCup) June 27, 2018
Two minutes into second-half stoppage time, Son's corner reached Kim at the far post and the offside decision that followed the defender burying the ball in the net was overruled by a VAR decision.
Low's side briefly rallied for an equaliser, but their legs were gone and when substitute Ju Se-jong hit a long ball forward to Son, the Tottenham man was able to run in behind Neuer and rub salt in Germany's wounds with the easiest of finishes.
Photo Getty Images. Caption: Mario Gomez and Mats Hummels of Germany react in the defeat to South Korea