Forward Kevin Schade has signed a five-year deal with Brentford and joins the Bees for a club-record undisclosed fee.
Schade began a half-season loan with the club from Freiburg in January 2023, which has now been made permanent.
After a promising start to his Brentford career, the 21-year-old has now extended his stay in west London until 2028.
Brentford director of football Phil Giles said: “When Kevin joined us on loan in January, we agreed with Freiburg that the move would become permanent this summer if certain conditions were met, which included Brentford remaining a Premier League team for next season.
"We have all been pleased with Kevin’s contribution so far, both on the pitch and his professionalism off it, so to have him with us now until 2028 is fantastic for the club.
"We all hope both Kevin and Brentford can make further progress from here and look forward to the challenge.”
Schade made his Brentford debut in the 1-0 defeat to West Ham United in the FA Cup on 7 January 2023, and excited Bees fans inside the Gtech Community Stadium that day with glimmers of his blistering pace and clever movement.
They were attributes that the German youngster, who is capable of playing anywhere across the front three, continued to show throughout his 19 appearances during the second half of the 2022/23 campaign.
He recorded his first assist for the club in the 3-2 west London derby victory over Fulham at the Gtech thanks to a burst of speed, before he cut the ball back to Mathias Jensen, who finished inside the six-yard box.
Schade also made his debut for the German national team in March 2023, when he came on as a substitute in a 2-0 friendly win over Peru.
He registered his first assist for his country later that month in a substitute appearance against Belgium - which Germany lost 3-2 - when he ran down the wing and found Serge Gnabry inside the penalty area, who scored a late consolation for his side.
Schade has been called up to the Germany Under-21s squad for their European Championship campaign this summer, which will begin on 21 June, with the final on 8 July.