Battle of Okehazama
In the First Oda Nobuhide defeated Imagawa Yoshimoto, setting the stage for his son, Oda Nobunaga, to become one of Japan's greatest warlords. Despite the defeat, later in 1548, Imagawa defeated Nobuhide in the Second Battle of Azukizaka and continued to expand his territory until 1560, when he faced Nobunaga and was killed in the Battle of Okehazama.