The phrase "youngest winner" refers to the person who achieved victory or success at a very young age, meaning they were the youngest person ever to accomplish something. Full definition
Within the last two weeks the Angels added a former Cy Young winner in Zack Greinke, the Dodgers added a former batting champion in Hanley Ramirez and the Yankees added a former MVP in Ichiro Suzuki. (sportsinsights.com)
She also became the second youngest winner of best actress in a leading role for 2012's «Silver Linings Playbook.» (backstage.com)