In August 1770, the two vanguard commanders; Chaophraya Phichairacha and Phraya Yommaraj Boonma proceeded to attack Sawangkhaburi. The town of Fang Sawangkhaburi itself was a small wooden fort without a proper city wall. The Thonburi forces laid siege on the town. During the siege, an elephant under the care of Chao Phra Fang gave birth to a young white elephant cub. White elephant was the symbol of the sacred kingship. Chao Phra Fang was shocked as this might be an omen suggesting that the kingship belonged to Taksin. King Taksin, upon learning about the white elephant, was also determined to possess the elephant. Thonburi besiegers easily took Sawangkhaburi. Chao Phra Fang fled into hiding along with the young white elephant.
