Heavyweight champion Vitali Klitschko stunned the boxing world Wednesday, announcing his retirement because of his recent knee injury.
Klitschko, 34, suffered a right knee injury while sparring last Thursday, just nine days before he was to make a long overdue mandatory defense against former champion Hasim Rahman. However, the injury forced Klitschko to postpone the match for the fourth time this year because of various injuries.
The knee injury, however, proved to be more than he could overcome.
"Lately, I have been spending more time with my injuries than with my opponents inside the ring," Klitschko said in a statement.
"The decision to retire from professional sports was a very difficult one, one of the hardest I have ever had to make. I love boxing and am proud to be the WBC and Ring [magazine] heavyweight champion. But I would like to end my career at its peak so I am retiring now as the champion to clear the way for my successors."
Klitschko underwent knee surgery on Tuesday in Inglewood, Calif., manager Bernd Boente told ESPN.com from Germany.
"He is done for good. He retires," Boente said.
With the retirement, Rahman, who had been the WBC interim champion, will become the full titleholder joining IBF champion Chris Byrd, WBA titlist John Ruiz and WBO beltholder Lamon Brewster as claimants to the heavyweight championship.
Tired of waiting for Klitschko, Rahman had defeated Monte Barrett in August to win the interim belt. Now, he is a two-time titlist.
"Vitali retired so there is no question who the champion is," Rahman said from Las Vegas. "I did everything I was supposed to do. I waited through all the postponements. I won the interim title in a fight against Monte Barrett that people said I was crazy to take. Klitschko retired, and I won my title the same way he did after Lennox retired.
"I beat the No. 2 guy [Barrett]. I tried to get the man inside the ring but I couldn't. But I did everything a champion should do. I had an excellent training camp and I was in incredible shape."
Once the interim tag is officially dropped from Rahman's title, promoter Don King will control all four of the title holders. He said he wants to do a tournament to crown an undisputed champion.
On Friday, Klitschko was diagnosed with a torn meniscus and bone bruise after Dr. Bert Mandelbaum examined him and looked at an MRI.
Klitschko, a Ukraine native living in Los Angeles with his wife and children, got a second opinion from orthopedic surgeon Dr. Tony Daly in Los Angeles on Saturday. Daly fit Klitschko with a brace to see if it would stabilize the knee, but after sparring just one round, Klitschko said he was still uncomfortable, and the fight was postponed.
Klitschko intended to see knee specialist Dr. Richard Steadman in Vail, Colo., this week but instead saw another specialist, Dr. Neal Elattrache, in Los Angeles.
Elattrache not only repaired the medial meniscus during the surgery, but also a ruptured ACL, which had not previously been diagnosed.
"It was a very bad injury," Boente said. "It was absolutely impossible for him to fight. The knee was totally unstable, and now we know why. He had a torn ACL. That is what Dr. Elattrache confirmed. He fixed it and the meniscus."
Said Elattrache: "The surgery took 1½ hours and was a complete success, but Vitali cannot compete in professional sports for the next six months. With this severe an injury it would have been absolutely impossible for Vitali to participate in a fight in the near future. The knee was totally unstable and it would have not held up."
Boente said it was important to Klitschko to go out "at the peak of my career with the title."
Klitschko was facing a deadline from the WBC to defend the title or else he would be stripped. Although the organization had not determined the specific deadline yet -- it was waiting for his medical report -- it could have been as little as 60 days and probably not longer than 90 days.
"The doctor said it would have been horrible if he had fought," Boente said.
"I think that this shows a lot of character on Vitali's part. He tried a brace and said, 'no way.' It was impossible. He could have done it, got in the ring for a couple of rounds and taken his money. But that would be the worst thing. It would have been very bad for boxing. That would have been another black eye. That would have been a horrible scenario. But Vitali didn't want to cheat the fans.
"It shows how stupid all these accusers are who say that he is ducking Rahman. It is absurd. As an athlete, this is one of the worst injuries you can have."
Klitschko was due to earn a minimum of $7.8 million, but probably would have earned closer to $10 million. Rahman, who is in bankruptcy, will miss out on a much-needed $4.2 million payday.
"There are still plenty of valuable opportunities out there," Rahman said. "There is still a Klitschko
fight that can be made. I can fight [Vitali's younger brother] Wladimir. Maybe he'll get in the ring
with me. You got Brewster, Byrd, [James] Toney. There are several viable fights to make for me. I am in a position of strength. I wont have a problem securing paydays."
Klitschko said he would turn his focus to working on social projects in the Ukraine, where he has been politically active.
"In the future, I plan to get more heavily involved and devote more energy to tackling social and socio-political challenges in my native Ukraine," he said.
Said Boente: "He's a smart guy. He will do other things."
Klitschko also will continue to work with his younger brother, Wladimir Klitschko, a top heavyweight contender.
Klitschko (35-2, 34 KOs), with a chiseled 6-foot-8, 250-pound frame, was considered by many to be the best of the heavyweight champions, largely based on his highly competitive loss to then-champion Lennox Lewis on June 21, 2003.
Klitschko was ahead on the scorecards but lost on a TKO when the fight was stopped after six rounds because of a terrible gash over his eye.
The brave performance against Lewis restored Klitschko in the eyes of many who were down on him after he had quit with a shoulder injury after nine rounds in a fight he was winning against Byrd in 2000.
Klitschko couldn't get a rematch with Lewis because Lewis retired six months later. Instead, after knocking out Kirk Johnson in two rounds, Klitschko faced South African Corrie Sanders -- who was coming off a knockout of Wladimir -- on April 24, 2004.
Klitschko stopped Sanders in the eighth round and made one defense, stopping Danny Williams in the eighth round on Dec. 11, 2004. But then a string of injuries kept him from facing Rahman.
They were supposed to fight on April 30 in New York, but a thigh injury forced Klitschko to postpone the fight until June 18. When the thigh injury had not healed fully, he postponed the fight until July 23. That date was postponed again until Nov. 12 after Klitschko needed minor back surgery. Then came the knee injury.
Rahman said he was over his initial disappointment of the fight being called off and that he was happy to get the title for a second time, even if it came in less dramatic fashion than when he scored a massive upset knockout of Lewis in 2001.
"The disappointment was there right after Klitschko pulled out," Rahman said. "I would rather fight him in the ring, of course. I would rather win the title by knocking someone out. There is no feeling better than that. But I put 10 weeks of training in and had my opportunity snatched from me on a phone call. That was utterly disappointing. But today, I am happy."
Said Rahman manager Steve Nelson: "We're happy that Rock is now two-time heavyweight champion, and that there is closure to this issue with Klitschko."
Klitschko becomes the second heavyweight in a row to retire as champion, joining Lewis. There hadn't been a heavyweight champion to retire with the title since Rocky Marciano in 1956. Gene Tunney also did it in 1928.
Dan Rafael is the boxing writer for ESPN.com.