Hamburg have signed Germany international Nicolai Muller after convincing Bundesliga rivals Mainz to sell.
The 26-year-old has put pen to paper on a four-year contract with the northern Germany side, who are reported to have paid Mainz 4.5 million euros for his services.
Mainz had last week said they would not sell Muller unless they received a considerable offer for the player, and were able to find a replacement.
"Nicolai is a player who improved constantly over recent years and is always able to reach an even higher level," said Hamburg's CEO Dietmar Beiersdorfer.
"That is in keeping with Hamburg and the aims we have to improve step by step.
"His versatility is going to be particularly helpful to our attack while his pace and strong shot will also help.
"Furthermore, Nicolai has always kept his feet on the ground, despite the success he has had."
One of those successes was earning his first caps for Germany before the World Cup, although he was not included in the squad which triumphed in Brazil.
He becomes Hamburg's fourth new signing this summer after Valon Behrami, Pierre-Michel Lasogga and Zoltan Stieber.