A woman had never been crowned The Biggest Loser before last night when Ali Vincent won the $250,000 grand prize for shedding a whopping 112 pounds, the most ever for a female contestant in Biggest Loser history.

Vincent, a 32-year-old hair stylist from Mesa, Arizona who nows weighs 122 pounds, first arrived on the Biggest Loser: Couples ranch with her mom Bette-Sue Burkland -- mom was voted off the show a while back but still lost 86 pounds -- and impressed both her competitors and TV viewers with her dramatic transformation.

Why did she take a leave of absence from her every-day life to work her butt off in front of a national audience? "I want to be strong and healthy and I want to look good and I want to set a good example," she says.

Vincent's inspiring story will be featured in PEOPLE magazine, available on Friday.