The Battle of Iwasaki Castle was fought between the forces of Niwa Ujitsugu and Ikeda Tsuneoki.
Though it was just part of overall Battle of Komaki and Nagakute, it played an important role in the outcome.

On the seventh day of the month, Ieyasu learned of Hidetsugu's encampment at Shinogi (modern-day Kasugai) through the information provided by farmers in Iga Province.
He entered into Obata Castle (Moriyama-ku, Nagoya) the following day and chose to pitch camp for the evening.
Early the next morning, he sent both the Niwa Ujitsugu and Sakakibara Yasumasa forces to chase after Toyotomi Hidetsugu, and followed shortly thereafter with his own.
Hidetsugu resumed his march on the eighth after hearing of Ieyasu's entrance to Obata Castle, but on the next morning, the situation changed very rapidly.
Ikeda Tsuneoki led the attack on Iwasaki Castle (modern-day Nisshin) and was promptly shot off of his horse.
Embarrassed by his fall, Tsuneoki forgot about the hit-and-run tactics and started a full assault on the castle.
Though the defenders fought well, the castle fell.
Niwa Ujitsugu, suffered numerous casualties including 300 killed, Ujitsugu's brother Niwa Ujishige being among the dead.

During the battle, Mori Nagayoshi, Hori Hidemasa and Hidetsugu all rested their forces at the modern-day cities of Owariasahi, Nagakute and Nisshin, waiting for the oncoming forces, as Ieyasu was closing in on them.
The Battle of Iwasaki Castle was fought between the forces of Niwa Ujitsugu and Ikeda Tsuneoki. Though it was just part of overall Battle of Komaki and Nagakute, it played an important role in the outcome.
On the seventh day of the month, Ieyasu learned of Hidetsugu's encampment at Shinogi (modern-day Kasugai) through the information provided by farmers in Iga Province. He entered into Obata Castle (Moriyama-ku, Nagoya) the following day and chose to pitch camp for the evening. Early the next morning, he sent both the Niwa Ujitsugu and Sakakibara Yasumasa forces to chase after Toyotomi Hidetsugu, and followed shortly thereafter with his own. Hidetsugu resumed his march on the eighth after hearing of Ieyasu's entrance to Obata Castle, but on the next morning, the situation changed very rapidly. Ikeda Tsuneoki led the attack on Iwasaki Castle (modern-day Nisshin) and was promptly shot off of his horse. Embarrassed by his fall, Tsuneoki forgot about the hit-and-run tactics and started a full assault on the castle. Though the defenders fought well, the castle fell. Niwa Ujitsugu, suffered numerous casualties including 300 killed, Ujitsugu's brother Niwa Ujishige being among the dead.
During the battle, Mori Nagayoshi, Hori Hidemasa and Hidetsugu all rested their forces at the modern-day cities of Owariasahi, Nagakute and Nisshin, waiting for the oncoming forces, as Ieyasu was closing in on them.
Battle of Komaki and Nagakute