.Pungluang's manager Pariyakorn Rattanasuban, criticised for not bringing Ambunda to fight in Thailand, believed her boxer should have won.
"I am very disappointed with the score," she said. "It is an unfair judging. I cannot accept that."
Pungluang also believed he should have won the fight.
"I was robbed," said the fighter, who added that he was a bit slow, compared to when he defeated AJ Banal to win the title in the Philippines.
"I am a bit rusty because I did not have a fight since October. However, I still believed that I boxed better than my opponent."
With the result, Ambunda extended his winning record to 20 while Pungluang suffered his second loss against 43 wins.
In Las Vegas, Cuba's Richar Abril defended his WBA lightweight title with a unanimous decision against Uganda's Sharif Bogere. The judges scored the bout 115-111, 116-110 and 116-110.
Bogere turned the bout into a brawl early, pressing forward to get inside and frustrate the taller Abril.
Abril was forced to wrap up Bogere in defence and both fighters tumbled to the canvas more than once.
Abril was docked one point in the eighth round for holding and Bogere was penalised one point in the 12th for leading with his head.
An accidental headbutt opened up a large gash over the right eye of Abril in the sixth round, which seemed to energise both boxers and sway the momentum toward the champion. AP