Juan Soto and Ronald Acuña Jr. are the 1st opposing players to HR in the same game before turning 21 years old since May 19, *1887*. The game was between the Indianapolis Hoosiers and New York Giants. Egyptian Healy (IND) and Mike Tiernan (NYG) did so that day (via @EliasSports)

— ESPN Stats & Info (@ESPNStatsInfo) July 21, 2018