"The match between Nhi and Tada was pretty old school and balanced, but the Vietnamese boxer had more effective attacks and also controlled the match well," Thaweekoon said.
After the Saturday match, all three judges gave Nhi the same score (96-94) and overall victory. However, Masato Yamashita, chairman of Japan Professional Boxing Association (JPBA), was not satisfied with the result and said a complaint will be sent to the World Boxing Organization.
"The match supervisor has already reported the results to WBO. The result cannot be changed," Thaweekoon added.
The Thai referee boasts experience of 26 years officiating pro boxing matches and can see Nhi going further in the future.
"If Nhi can maintain her current fighting style, she would be champion for a long time," he said.
Nhi said she is willing to accept a rematch if Tada is not happy with the result.
"Tada is the toughest opponent that I have ever faced. If she doesn't agree with the result, she can challenge me like I did with her. I'm always ready to get a rematch," Nhi said.
With the victory over Tada, Nhi, 25, has become the eighth mini-flyweight champion in the history of WBO. She is also the first world boxing champion from Vietnam.
Before that, she claimed the WBO Asia-Pacific belt in February 2020. In her professional career, she has fought five matches and won them all.