Hill was the first National Leaguer to serve as a designated hitter in regular season play , doing so on June 12 , in the first - ever game in interleague play as his San Francisco Giants faced the Texas Rangers at The Ballpark at Arlington .
Hill was the first National League player in regular season play ever to serve as a designated hitter . 
 The distinction occurred on June 12 , in the first - ever game in interleague play as his San Francisco Giants faced the Texas Rangers at The Ballpark at Arlington .