Steve Dunning Wikipedia
"Stunning" Steven John Dunning (born May 15, 1949, in Denver, Colorado) is a former professional baseball player who played seven seasons for the Cleveland Indians, Texas Rangers, California Angels, Montreal Expos, and Oakland Athletics of Major League Baseball. He was the second player to go straight to the Major Leagues after being drafted without spending a day in the minors.
On May 11, 1971, Dunning had the distinction of hitting a grand slam home run off of Oakland Athletics pitcher Diego Seguí. This remained the last grand slam hit by an American League pitcher until Félix Hernández of the Seattle Mariners accomplished the same feat June 23, 2008 in a game against the New York Mets.