Teenage amateur Chakansim Khamborn won the third leg of the Singha-SAT Thai LPGA 2016 at Bangkok Golf Club in Pathum Thani.
The 16-year-old from Khon Kaen, who yesterday made a closing 69 with six birdies and three bogeys, grabbed the title on 208 at the par-72 course.
She was five strokes ahead of runner-up Saranporn Langulgasettrin (72) in the 54-hole tournament.
The top purse of 114,000 baht went to Saranporn, who also won last week's All Thailand Golf Tour event in Nakhon Nayok.
Chakansim said she was excited to have won her first professional event following her successes at a number of amateur competitions.
"It is a big thing for me because to win here, I had to outperform lots of professional players," said the teenager.
She will next play in some amateur events in the US.
Phuket native Saranporn, also 16, said she tried her best to win the title for her grandfather, who passed away a few days ago, but her bid was unsuccessful.
"I have gave it my best shot, but Fai [Chakansim's nickname] was putting so well. She deserved to win," said Saranporn.
Saranporn is next scheduled to play in the US$150,000 Hong Kong Open from June 10-12.
Pimnipa Panthong shot a 69 for a 214 total to finish third, one stroke better than fellow amateurs Nattapan Siritrai (67) and Tundra Piddon (70), who shared fourth spot.