The former world junior No 1 relied on her expertise on grass to win the match in one hour and 47 minutes. It was her first maindraw ITF match win since reaching the second round in Hong Kong in January. The win was also a revenge for the Thai who lost to the Japanese foe 1-6 2-6 in a small ITF event in Khaosiung last year.
Noppawan, who just graduated her degree in laws from Bangkok University this year, will play either eighth seed Freya Christie of UK or Russian Natela Dzalamidze, winner of an ITF event in Hua Hin last year, in round two.