Undefeated boxing star Terence Crawford announced his retirement from the sport Tuesday.

“Walking away as a great with nothing else left to prove,” he said in a post on X.

Crawford reached the top of the sport before leaving the ring. He won the biggest fight of his career in September when he defeated Mexican great Canelo Alvarez to become the undisputed super middleweight world champion.

That victory made Crawford the first boxer in modern history to be an undisputed champion in three divisions (light welterweight, welterweight, super middleweight).

Crawford, 38, retires 42-0 all time with an impressive 31 wins via knockout. He won 18 major world championships across five weight classes in a professional career that began in 2008.

The native of Omaha, Neb., was the No. 1 pound-for-pound fighter in boxing at the time of his retirement.

“I’m stepping away from competition, not because I’m done fighting but because I’ve won a different kind of battle. The one where you walk away on your own terms,” Crawford said in a YouTube video. “This isn’t goodbye, this is the end of one fight and the beginning of another.”

He added: “I gave this sport every breath I had. Every scar, every triumph, every ounce of my heart. I’ve made peace with what’s next. And now, it’s time. Thank you.”

–Field Level Media