By Jeremy Harness

AP photo: USGA’s Mirim Lee drives into the ball at the ninth tee in the first round Lee shot a eight under par 64 at the U.S. Women’s Open Golf Tournament at CordeValle on Thursday

SAN MARTIN–The U.S Women’s Open is supposed to serve as the ultimate test to the world’s best female golfers. For most, that has already proven to be true.

Mirim Lee, on the other hand, seemed to just breeze right through that test.

The Korean grabbed a three-shot lead in the opening round of this tournament at CordeValle Golf Resort with an eye-popping 64.

In doing so, Lee shot the second-lowest score in the history of this tournament, with the only mark lower occurred when Helen Alfredsson shot a 63 in the opening round of the 1994 event.

Lee certainly had her game going, but she also benefited from having played in the morning, when the conditions on and around the course were calm while the greens were soft and receptive.

“I think everything was good,” said Lee, whose best finish this year is a tie for fourth at the KPMG Women’s PGA Championship one month ago. “Like driver is good, and then iron is good.”

“The course is perfect now.”

As the afternoon rolled around, all of that changed, and the LPGA’s premier players found that out the hard way on Thursday.

The world’s number-one player, Lydia Ko played alongside the second-ranked Brooke Henderson and the fourth-ranked Lexi Thompson in the afternoon, and the trio could not come close to matching Lee’s level.

Ko finished the opening round with a one-over 73 while Thompson shot a 74, and Henderson closed out Thursday’s proceedings with a four-over 76. It was a considerable step back for Henderson, who is fresh off of her victory at the Cambria Portland Classic, which she won by four strokes.

Meanwhile, San Jose native Christina Kim is continuing her strong play. She shot a two-under 70 on Thursday and is currently tied for 11th.

“I’ve been swinging really, really well, and I’ve been putting really, really well,” Kim said. “Plus, I turned 32 this year, and my dad is like ‘You played pretty good when you were 16, so why don’t you try to pretend like you’re only half your age when you’re on the golf course.’