Matched Inbee Park to the day (19 years, 11 months, 17 days) as the youngest champion in U.S. Women's Open history when she defeated Nasa Hataoka in an aggregate-score playoff at The Olympic Club in 2021. It was her first victory on the LPGA Tour and third worldwide. She became the first player from the Philippines to win the U.S. Women's Open, although a few months after the victory, Saso declared that she was now representing Japan, the country of her father. She is a dual citizen of Japan and the Philippines, the country of her mother. Saso enjoyed a highly decorated junior/amateur career before turning pro in the fall of 2019. Saso was the stroke-play medalist in the 2019 U.S. Girls’ Junior and lost to Jillian Bourdage in the semifinals. Saso also was a semifinalist in the 2016 U.S. Women’s Amateur, defeating Hataoka in the quarters. Saso turned pro in November of 2019, and quickly won a pair of LPGA Tour of Japan events in 2020: the NEC Karuizawa 72 and Nitori Ladies Golf Tournament.