Mainz forward Andre Schurrle will join Bayer Leverkusen on a five-year contract next summer.
The 19-year-old has caught the eye in the early stages of the season and several European clubs sent scouts to Mainz's 2-1 win over Kaiserslautern last weekend.
However, Leverkusen have won the race ahead of the competition by signing the player for an undisclosed fee.
"We are delighted to have been able to sign Andre Schurrle, one of the biggest talents in German football, on a long-term contract," said Leverkusen general manager Wolfgang Holzhauser on his club's official website.
Coach Jupp Heynckes is looking forward to working with Schurrle next season.
"He is an outstanding talent in the Bundesliga and we are glad that he has chosen Bayer Leverkusen," he said.
"We think he can take a greater step in his career with us on an even higher level."