Yuka Saso shot a 6-under 66 in the final round to finish second, one stroke back from first-time LPGA winner Jodi Ewart Shadoff of England at the Mediheal Championship on Sunday.
The 21-year-old Saso went 14-under for the tournament following rounds of 70, 70 and 68 over the first three days at the Saticoy Club.
She birdied four of the last five holes to finish one shot ahead of England's Georgia Hall, American Danielle Kang and South Africa's Paula Reto in a tie for third.
The 2021 U.S. Women's Open champion's last round included six birdies overall, plus an eagle on the par-5 eighth, against a pair of bogeys.
"There was no wind, and that allowed me to hit good shots and get into a good flow," Saso said. "On the final hole, I didn't know where I was on the leaderboard, but I'm glad I got the birdie. I was able to play patient golf and gain good experience."
Ewart Shadoff broke through in her 246th start, closing with a 1-under 71 in a nervy final round. The 34-year-old blew a four-stroke overnight lead and conceded the top spot to Reto at the turn before edging back in front in a battle down the back nine.
Hinako Shibuno, the 2019 Women's British Open champion, was next-best among the Japanese players, tying for eighth at 10-under following a final round of 71.