Wladimir Klitschko
via Instagram / Wladimir Klitschko

Following back-to-back losses, former heavyweight boxing champion Wladimir Klitschko has announced his retirement.

The 41-year-old made the announcement on Thursday (Aug. 3), ending a 21-year professional boxing career where he fought in more heavyweight title bouts than anyone, notes ESPN.

Klitschko last fought on April 29 in sold-out fight at Wembley Stadium in London — his 29th heavyweight title fight appearance. He lost to Anthony Joshua via TKO.

Despite losing, it was a dramatic fight in which both fighters got knocked down. Klitschko went down three times in all and was stopped in the 11th round.

It followed a loss to Tyson Fury in Nov. 2015, via unanimous decision, costing him the unified world championship he had held for nearly a decade.

“I deliberately took a few weeks to make my decision, to make sure I had enough distance from the fight at Wembley Stadium,” Klitschko said in a statement. “As an amateur and a professional boxer, I have achieved everything I dreamed of, and now I want to start my second career after sports. I would have never imagined that I would have such a long and incredibly successful boxing career. I’m very thankful for this. Thanks to everyone who has always supported me especially my family, my team and my many fans.”

During his boxing career, Klitschko won the Olympic super heavyweight gold medal as an amateur in 1996, became a two-time world champion as a professional and earned hundreds of millions of dollars.

Check out some of his greatest hits below: