Mike Trout of the Los Angeles Angels became the youngest AL Rookie of the Year, a unanimous winner Monday after a season that put him in contention for the MVP award, too.
The 21-year-old centre fielder hit .326 with 30 homers and 83 RBIs following his call-up from the minor leagues in late April.
The NL Rookie of the Year was later announced, with Washington outfielder Bryce Harper the winner.
Trout received all 28 first-place votes from the Baseball Writers' Association of America, becoming the eighth unanimous AL pick and the first since Tampa Bay's Evan Longoria in 2008.
Detroit second baseman Lou Whitaker had been the youngest AL winner in 1978, but he was 2 months, 26 days older than Trout when he took home the award.
Trout received the maximum 140 points. Oakland outfielder Yoenis Cespedes was second with 63, followed by Texas pitcher Yu Darvish (46), who joined Trout as the only players listed on every ballot.
Harper got 16 of 32 first-place votes and 112 points from the NL panel. Arizona pitcher Wade Miley was second with 12 first-place votes and 105 points, followed by Cincinnati slugger Todd Frazier with three firsts and 45 points.
In addition to Trout and Longoria, the only other unanimous AL winners were Nomar Garciaparra, Derek Jeter, Tim Salmon, Sandy Alomar Jr., Mark McGwire and Carlton Fisk.
Trout spent some time in the majors last year but still retained his rookie status. He began this season in the minors and made his first big league appearance this year on April 28. His season put him in contention for the AL MVP award along with Triple Crown winner Miguel Cabrera of Detroit. That voting is announced Thursday.
For winning the award, Trout earned a $10,000 bonus on top of his $482,500 salary.