|Polish-born Sosnowski, right, believes Klitschko is 'already over the hill' [GALLO/GETTY]
WBC world heavyweight champion Vitali Klitschko has confirmed he will defend his title against European champion Albert Sosnowski from Poland on May 29.
The fight will take place in Schalke's football stadium, in Gelsenkirchen, Germany.
"He is experienced, he is fast and he is a tough boxer who will try everything to take my belt. But I will not let it happen," Klitschko said in a statement.
"I promise all fans an unforgettable evening."
The 38-year-old Ukrainian Klitschko, whose brother Vladimir will defend his WBO, IBF and IBO titles against Eddie Chambers on March 20, said Sosnowski, 31, would be a tough rival.
Sosnowski, the 31-year-old European Boxing Union heavyweight champion with 45 wins, two defeats and a draw, was due to defend his European title against Audley Harrison in London in April but cancelled to fight Klitschko.
Sosnowski said the fight was a "dream come true".
"Because of the Harrison fight I am already in training and suddenly here comes the once-in-a-lifetime chance to fight Klitschko. I want to thank him and his team for giving me that opportunity which I will definitely take.
"For me, Klitschko is already over the hill. I know that I am the underdog for everybody, but I tell you, Klitschko will regret that he picked me.
"Many Polish and Germans with Polish roots live in the Gelsenkirchen area and I hope that they will support me. I will be the first Polish heavyweight champion of the world."
The 38-year-old Klitschko has 39 career wins and two defeats and the Hamburg-based boxer was also anticipating a strong fan base in Germany.
"I'm very happy to have my next fight in Germany again. The arena in Gelsenkirchen and the fans there are very special,” he said.
"I experienced that last year when my brother Wladimir had his fight there in front of 61,000 spectators. The atmosphere was simply electrifying.