The Imagawa forces had entered Owari Province, the domain of Oda Nobunaga, intent on capturing Kyoto. They had moved relatively unhindered through Mikawa (eastern Aichi Prefecture) and were set on crossing through Owari (western Aichi). Stopping at Dengaku-hazama, they were celebrating their recent victories over the Oda held castles and fortresses with food and drink, and believing themselves to be safe, had removed their armor and were relaxing in the heat then the Oda warriors struck.

Hearing the commotion as enemy samurai stormed the camp, Imagawa Yoshimoto thought it to be a drunken brawl among his own men. Emerging from his curtained off enclosure, he was surprised to find Oda samurai bearing down on him. The first thrust a spear at Yoshimoto, who parried, cutting through the spear shaft and into its wielders leg. A second samurai took the generals head.

The site of the battle is contested, with two "official" sites listed. One, designated as the battle site in 1937 by the Ministry of Education, can be found in Minamiyakata, Sakae-cho in Toyoake City. This site, just off National Route 1, the old Tokaido, contains a grave to Imagawa Yoshimoto, a memorial stone, and the Shichikokuhyo, or Seven Granite Pillars representing the Imagawa's seven generals.