The son of Thomas Duerson Knight, an attorney, and Helen Whitaker (Fowle) Knight, daughter of Governor Fowle of North Carolina, Duerson Knight was a track star at University High School and the University of Chicago (class of 1916). He joined the United States Air Service in 1917. He was commissioned as a 1st Lieutenant on 22 March 1918. To gain combat experience, he was temporarily assigned to the Royal Air Force. Flying the S.E.5a with 1 Squadron, he scored his first victory on 27 May 1918 and became an ace in less than a week. By August 1918, he achieved ten confirmed victories before being reassigned to a squadron in the United States Air Service in September 1918. Knight returned to the University of Chicago in 1919.