Bob Allison and Harmon Killebrew hit grand slams in the 1st inning to lead the Minnesota Twins to a 14 – 3 victory over the Cleveland Indians.
On May 18, 1962 — Bob Allison and Harmon Killebrew hit grand slams in the 1st inning to lead the Minnesota Twins to a 14 – 3 victory over the Cleveland Indians.
Source:
Baseball Reference May 18