She shot a seven-under-par 64 at the Evian Resort Golf Club in France, to take to take a two-stroke lead, her best start in the tournament.

Four players are tied for second, including 2015 champion Lydia Ko of New Zealand.

Joining her are Alison Lee of the United States, three-time LPGA Tour winner Céline Boutier of France, and Thai international Wichanee Meechai.

Reto, who managed eight bridies, was in good spirits after the first day.

It is understandable after missing the cut last year 2022 and withdrawing in 2021.

"This golf course is so fun and the views and everything, it's just awesome to be here," she said.

"But hit some good quality shots beginning of the round.

"Just gave myself opportunities.

"One birdie dropped and you sort of try to do the same thing over and over and just put yourself in good spots on this golf course."

In a tie for sixth at -4, nine players are queuing including three major winners in South Koreans Kim A-lim and Ji Eun-hee and Yuka Saso of Japan.

With four birdies and two bogeys, defending champion and Canadian star Brooke Henderson is tied for 19th.

A total of 16 are tied for 19th, including National Collegiate Athletics Association champion Rose Zhang of the United States.