Claressa Shields: “I am a once-in-a-lifetime athlete.”

Claressa Shields, the 31-year-old undefeated boxer with an 18-0 professional record and two Olympic gold medals, will fight Australian Kaye Scott on Saturday night in Atlanta, Georgia. Shields, the current undisputed heavyweight champion, is dropping down to middleweight (160 lbs) for the first time in three years to challenge Scott's WBC and WBA world middleweight titles. The two fighters have a history from their amateur days, having sparred together on at least one occasion.