I really didn't think I could hit that far, to tell you the truth. It just happened.--Zack Greinke
I am nearly certain that Steve Busby hit a home run for the Royals at Municipal Stadium in September of 1972.
Tom, thanks so much for reading and commenting. Busby is not credited with hitting a HR, but thanks to your comment I discovered a grand slam that Busby hit in September '72 that was not counted since someone had called time right before he hit it. Busby mentions it in this interview: http://royals.scout.com/2/633993.html and it is also mentioned in the game summary here: http://news.google.com/newspapers?id=tNAfAAAAIBAJ&sjid=ENkEAAAAIBAJ&pg=784,1493701&dq=steve+busby+grand+slam&hl=enHe still had a nice day at the plate: 3-for-4 with three RBI! They were only three hits of his career...only got 15 at-bats as a September call-up in '72 and then came the DH in '73.