King Naresuan then marched his army to combat the invader. They met at Nong Sarai. Supan Buri district. King Naraesuan had a fight on elephant back with Phra Maha Uparacha. King Naresuan was able to kill his rival but he could not destroy the enemies army because his soldiers were further behind. King Naraesuan was full of rale when he came back to Ayutthaya and wanted the commanders to be executed because they were unable to follow him. However, Phra Wanratana of Wat Pa Kaew asked him for the death penalty and suggested him to build a Chedi to celebrate the victory instead. King Naraesuan the Great then decided to construct a large Chedi in this monastery named Phra Chedi Chaimongkhon. This monastery became Wat Yai Chaimongkhon later on.