Yes sir! It was Stan the Man. Score the run please, Arlo. The second person to achieve this feat was actually in attendance the day that Stan did it.
He was the starting 1st baseman for the Padres from 1969-1974, as well as logging a few games with Houston in '67-'68, and with Detroit, Oakland, and Montreal in '75 and '76. This player hit 173 HR's for his career, never more than 38 in a season.
Any guesses on his name, or should I just reveal the answer here?