Japan stunned Germany with a late comeback in their World Cup opener, with goals from Ritsu Doan and Takuma Asano seeing them win 2-1 at the Khalifa International Stadium.
Japan had never previously beaten their European opponents, but they capitalised on German errors and missed chances to secure a famous victory in the first game of Group E.
Striker Thomas Muller said after the game: "It is ludicrous that we are here with a defeat. We played a good game over long periods of time but a game is also marked by the chances that you convert into goals."
Japan had an early 'goal' from Daizen Maeda ruled out for offside too, but Hansi Flick's side soon went ahead after a clumsy challenge from goalkeeper Shuichi Gonda on David Raum gave them a penalty and Ilkay Gundogan slotted home from the spot (33).
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Germany thought they had scored a second at the end of the first half, but Kai Havertz's strike was also ruled out for offside.
The four-time World Cup winners continued to see chances come and go - Gundogan hitting the post on the hour - before Japan used their lightning quick attack to score twice late on.
Four minutes after coming on as a substitute, Doan (75) turned home from close range after a Manuel Neuer save. Germany were then caught out with a ball over the top, allowing Asano (83) to smuggle the ball home on a tight angle.
Each Japan goal was greeted with a team bundle at the corner flag, and there were joyous celebrations at full-time. "It's a big surprise. We saw the Saudi victory over Argentina - the Asian countries are reaching the global standard," Japan coach Hajime Moriyasu said.
For Germany, their poor World Cup form continues, having finished bottom of their group at the 2018 tournament.
How Japan secured a famous victory
Japan started brightly and had the ball in the net inside seven minutes. Gundogan was muscled off the ball in midfield before Junya Ito drove down the right flank. Maeda then slotted home his cross, but he was a yard offside.
Germany soon began to find their feet and had a string of chances after the 20-minute mark. Joshua Kimmich saw his effort from distance palmed away by Gonda before Gundogan skied the rebound. The Man City midfielder then saw an effort go straight at Gonda, before another attempt a minute later was well-blocked.
But for all Gonda's good work in the opening half hour, his sloppy goalkeeping then gave Germany a penalty as he raced out to meet Raum, tipping him over before catching the defender again and almost landing on top of him.
After having two earlier efforts blocked, Gundogan stepped up and expertly dispatched his spot-kick to see the four-time World Cup winners in front.
Germany then began to dominate and thought they had a second in the third minute of four added on at the end of the first half. Havertz slotted home from a Serge Gnabry cross, but, after a VAR check, the goal was rightly ruled out for offside.
Japan could have made the end of the first half more interesting still, but Maeda directed a header just wide of the target.
It was an end-to-end start to the second half, and Gundogan should have added another on the hour. The impressive Jamal Musiala drove down the left before setting up the midfielder from 15 yards out. However, Gundogan's effort smashed off the bottom of the post and went wide. In the 70th minute, Gonda also denied Jonas Hoffman and Gnabry in quick succession.
But the Japan comeback was on the horizon, with Neuer's first save of the game coming soon after, denying Asano. He made another superb stop during the build-up to Japan's equaliser too, getting a hand to Takumi Minamino's cut-back, but Doan was lurking inside the area to slot home from close range.
However, Neuer would have wanted to do better for Japan's winner. A long ball over the top down the right picked out Asano in behind the defence, with the forward driving into the area. He held off Nico Schlotterbeck before squeezing the ball past the goalkeeper and into the far corner.
It was a frenzied end to the game as Germany pushed for an equaliser. Leon Goretzka flashed a volley wide of the post as Neuer came up to provide another body in the area, but it proved ineffective. Every clearance was celebrated like a goal by the Japan bench as they held on for a vital three points.
Germany cover mouths in free speech protest before kick-off | Minister wears OneLove armband
Ahead of the kick-off, Germany players covered their mouths in their team picture in an apparent freedom of speech protest.
It came after a number of European football associations were threatened with FIFA sanctions if they wore a 'OneLove' armband during the World Cup.
The DFB later tweeted about the gesture, saying: "With our captain's armband, we wanted to set an example for values that we live in the national team: diversity and mutual respect.
"Be loud together with other nations. This is not about a political message: human rights are non-negotiable. That should go without saying. But unfortunately it still isn't. That is why this message is so important to us. Banning us from the bandage is like banning our mouths. Our stance stands."
German Federal Minister of the Interior and Community Nancy Faeser also wore a OneLove armband at the match following FIFA threatening sporting sanctions for wearing the armband.
Flick and Neuer admit: We are under pressure
Germany manager Hansi Flick:
"With this defeat and zero points, we are under pressure, no question about it. We can only blame ourselves. It's a great disappointment.
"We were on the right path in the first half, we had 78 per cent possession and were ahead 1-0. Then we had good chances in the second half that we didn't take advantage of.
"Japan were simply more efficient today. We made mistakes that we should never commit especially in a World Cup and those are the things that we need to improve on."
Germany goalkeeper Manuel Neuer:
"I am totally frustrated and angry that we let this game slip, it was not necessary. After the break we no longer had this game flow and did not play with the same confidence as in the first half.
"We are now under pressure from the start. That was also the most important game of how you start in a tournament but we messed it up."
Japan coach Hajime Moriyasu:
"We wanted to start playing aggressively, we wanted to dominate the game. But Germany are very strong so we needed to defend persistently and take our chances.
"At the end they came at us with the full power, in the past maybe we would have lost but the players have been playing in Germany and Europe they've learned so much from that, so we held on.
"United as one, we needed to hang tough until the final whistle went and we were able to grasp our opportunity."
Pundits: 'A massive shock'
Sky Sports' Gary Neville on ITV:
"Absolutely, I expected Germany to win that game. It's a massive shock. Japan are no mugs but it just shows that when you're not quite at it, you will get a big surprise. What surprised me with the second goal was that Manuel Neuer turned his body to allow the ball to go past him.
"Usually, Neuer stands up strong and is a brilliant goalkeeper. The result will send shockwaves through the tournament."
Sky Sports' Graeme Souness on ITV:
"It's an almighty blow. When you're a coach, and if you're the Spanish manager, the result has in part filled his team talk [against Costa Rica]. He'll be reminding them they could slip up tonight unless they're bang on it."
Sky Sports' Roy Keane on ITV:
"Of course, the result hasn't just come out of nowhere, but when you're playing Germany - we spoke about them learning from the past mistakes of the last World Cup - you're 1-0 down.
"It's a long way back and so the [Japan] manager deserves huge credit. He had to make those changes and it was part of his game plan as he had to freshen things up.
"They were clinical. There were question marks about Neuer for the second goal, but you can't begrudge them their victory.
"There was never any doubt they would bring the spirit, fight and energy to the party, but they've shown intelligence and great quality.
"Often, you see substitutes who can't get up to speed with the game, but all of them had an impact to lift their team-mates around them. They all affected the game.
"They've lifted their country."
What does the result mean?
After the opening two games of Group E, Germany sit third after Spain beat Costa Rica 7-0 later on Wednesday. Japan sit second behind the 2010 winners.
Both teams play again on Saturday as Germany take on Spain - which had been viewed as a shootout for first and second spot in the group, but could now see Germany on the verge of an exit if they lose - while Japan face Costa Rica.
In the final group games on Thursday December 1, Germany will play Costa Rica while Spain face Japan, who will be hoping to cause another upset against one of Europe's most successful sides.
Opta stats - Japan's historic win
- Japan came from behind to win a World Cup match for the very first time, having drawn two and lost 11 of their 13 matches when they had trailed before today.
- Having lost their opening game at just one of their first 18 World Cup tournaments (W13 D4), Germany have lost their first game at each of the last two World Cups.
- Through Ritsu Doan and Takuma Asano, Japan became the first side to have two substitutes score in a single World Cup game against Germany.
- Since 1966, only Yoshikatsu Kawaguchi in 2006 (10 vs Brazil) has made more saves in a single World Cup game for Japan than the eight Shuichi Gonda made today.
Player of the match - Jamal Musiala
He may have been on the losing team, but Germany's Musiala lit up the Khalifa International Stadium. He showed superb skill throughout, particularly in the second half and is set to have a breakout tournament in Qatar.