IBF and WBO heavyweight champion Wladimir Klitschko says he is in the best shape of his life going into his defense against American challenger Eddie Chambers. (AP) DUESSELDORF, Germany — IBF and WBO heavyweight champion Wladimir Klitschko says he is in the best shape of his life going into his defense against American challenger Eddie Chambers. The 33-year-old Ukrainian hasn't fought in nearly 10 months but says he won't be rusty when he fights his former sparring partner Saturday in Duesseldorf's Espirit Arena.

"I've never been so fast, I've never been so agile, I've never been so experienced as I am now," Klitschko said ahead of his 17th title fight. "I am hungry. I am on fire. He wants my title but I won't allow it." Klitschko (53-3, 47 KOs) last fought in June, stopping Ruslan Chagaev in a hastily organized fight.

The 27-year-old Chambers (35-1, 18 KOs), gives away 13 centimeters (five inches) in height to Klitschko, who also has a similar reach advantage. "I have a great chance," Chambers said. "I want to shock the world. It's the biggest challenge of my life."

Chambers' trainer, Rob Murray, said the fight will provide "something very special to see" and predicted the American will win comfortably. Whether Chambers has the punching power to upset the younger Klitschko brother remains to be seen.

"I have to avoid his jab and score points inside," Chambers said.

Chambers beat Alexander Dimitrenko in July to become the WBO's No. 1 contender. His only defeat was against Alexander Povetkin in Berlin in January 2008. Klitschko, whose last defeat was against Lamon Brewster in 2004, said he won't be underestimating Chambers.

"He has an unorthodox style and he is very dangerous," Klitschko said. Klitschko's trainer Emanuel Steward predicted a knockout win for his fighter.

"Chambers is the best he's ever fought, but Wladimir is in the form of his life and he'll win by KO by round 8 at the latest," Steward said. About 46,000 of the 51,000 available tickets have been sold for the fight at the football stadium that has a retractable roof.

Vitali Klitschko, Wladimir's older brother, will defend his WBC heavyweight title against Polish-born fighter Albert Sosnowski on May 29.