World heavyweight champion Lennox Lewis announced his retirement from boxing in London Friday.
The 38-year-old heavyweight champion said the time had come for a new generation to take over the sport.
Facing a March 1 deadline to confirm a rematch with the contender, Ukraine's Vitali Klitschko, whom he defeated in a tough bout last June, Lewis told a London news conference he had done everything in the sport he set out to accomplish, and wanted to bow out while still at the top.
"It is not easy being heavyweight champion of the world," Lewis said. "It is in fact very hard to achieve becoming heavyweight champion of the world. It is even harder to keep and stay at the top. I am a person who believes if you cannot give a 110 percent, then you should not do it. Right now I have given a hundred-and-ten percent in my sport."
Lewis is the first reigning heavyweight champ to retire since Rocky Marciano nearly 50 years ago.
Lewis said his decision was not easy to make, but he has no regrets.
"I respect boxing a great deal. Boxing has done so much for me," he said. "And one of the reasons why I am retiring (is) out of respect for the sport as well. I respect the sport so much that it is time for the younger generation of boxers out there, you know, to make their own route to become the heavyweight champion of the world."
As a professional, Lewis won 41 of his 44 fights, lost two and drew one.
As an amateur, he won the Olympic super-heavyweight gold medal for Canada at the Seoul games in 1988.