From June to September 1900 he was deployed to China as a crewman on the cruiser Kasagi, which was sent to support Japanese naval landing forces which occupied the port city of Tianjin in northern China during the Boxer Rebellion, as part of the Japanese contribution to the Eight-Nation Alliance.

During the Russo-Japanese War, he served in various staff positions and was promoted to lieutenant commander on August 5, 1905.

Nozaki graduated from the Naval War College in December 1907 and was promoted to commander in March 1910.

[1] He received his first command, that of the cruiser Niitaka on October 30, 1914 and was promoted to captain in December of the same year.

Afterwards, he was an inspector at the Yokosuka Naval Arsenal to April 1919, when he returned to sea as captain of the new battleship Kongō to November 1919.