Here is a list of Niyomtrong's best fights. For a list of Niyomtrong's losses, refer to "Thammanoon Niyomtrong Losses".
On March 6, 2018 Thammanoon Niyomtrong met Toto Landero in a strawweight (WBA) world-title defense fight. Niyomtrong was 27 years old and with a record of 17-0 (7), and Landero was 22 years old and with a record of 10-1-2 (2). Niyomtrong won the fight via 12-round unanimous decision and successfully defended his title.