RB Leipzig moved into the semi-final of the Uefa Champions League on Thursday after a 2-1 victory over Atletico Madrid.
Tyler Adams hit an 88th-minute winner for the German outfit who were playing in the knockout stages for the first time.
His decider came after a Joao Felix penalty for Atletico had cancelled out Dani Olmo's opener for Leipzig early in the second half.
"We had trained for the situation when we went 1-0 up, but things didn't work out exactly as planned,” said Leipzig coach Julian Nagelsmann.
"The boys sorted things out for themselves and showed how mentally strong they are, so I am really proud of them."
But they paid the price for their cagey approach. "We didn't have that physical sharpness or rhythm," said Atletico coach Diego Simeone.
"We came with a lot of hope. The feeling is a lot of bitterness but I know the players gave everything. They gave it their all,” Simeone added.
Eleven years after their founding, Leipzig will face Paris Saint-Germain on 18 August for for a place in the final on 23 August. It will be a clash which pits master against the apprentice.
PSG boss Thomas Tuchel, while he was coach at Augsburg 12 years ago, gave Nagelsmann his first break as a scout after the 21-year-old had to retire from playing due to a knee injury.
"They are a top team with a top trainer," said Nagelsmann. "I have often played as a coach against Thomas but rarely won.
"I would be satisfied with a bad game if we win," Nagelsmann added.
"They are a team full of stars. It's clear that we need another top performance to get into the final."
Leipzig skipper Yussuf Poulsen, who joined in 2013 when Leipzig were in Germany's third division, added: "This is a story that you couldn't have written better. It is a great day, a great moment, we have to enjoy it and then have a better game in the semi-finals in five days."