Play a pick-up game on Tin Can Alley, tee-ball, then load the team up with heavy hitters (My team below).
Once in the game, aim the hitter either Open or Closed to hit off to the right with a Power swing. You are aiming for a high ball down the right field/foul line. If it hits correctly it will bounce off the closed green dumpsters or the wooden crate behind them and bounce off-screen to the right. That should trigger a home run which will pop the achievement.
My Team:
Keisha Phillips
Mark McGuire
Luke Lopez
Achmed Khan
Juan Gonzalez
Pete Wheeler
Tony Gwynn
Pablo Sanchez
Mikey Thomas
You can also hit it normally out of park if you get lucky but this is much more consistent/easier to do.