Since 1940, he was a commander of the Petropavlovsk naval base of Pacific Fleet. Dmitry was a participant in Soviet–Japanese War in 1945. During Invasion of the Kuril Islands, he has prepared, and in difficult weather conditions has accomplished a transition by the sea, executed landing operation to fortified islands of Shusha and Paramushir, and has organized a neutralization of enemy's strong points and weapon placements. For the successful realization of this operation, he had been given the rank of the Hero of the Soviet Union. After that, he continued his service to the navy. In 1948, Ponomarev has ended the academic courses. Since 1954, he was living in Leningrad, and died in 1982.