A rocky back-nine has left New Zealand golfer Lydia Ko four shots behind the world's latest teenage golf sensation after the opening round of the US Women's Open.
Ko, who knows what it's like to lead tournaments while still growing up, dropped four shots in four holes on her way back to the clubhouse on the Lake Course at the Olympic Club.
The two bogeys and one double bogey took Ko from a very strong position at three-under par, to the middle of the pack, before a birdie on the 17th left the world's eighth-ranked golfer at even par for the day; enough to sit in a tie for 16th.
Despite those inconsistencies, Ko herself was happy with her game on a course she says can be extremely unforgiving.
"You have to be grinding out there and be patient. Birdies are hard and it's easy to make mistakes," Ko told media following the round.
"Overall I played solid. Two not-so-good holes, but other than that I felt like I played solid. So hopefully I kind of keep that momentum going into tomorrow."
However, Ko's own time with the media was overshadowed by the performance of high schooler Megha Ganne who became the first amateur in 15 years to have a share of the lead after any round at the event.
The 17-year-old from New Jersey made back-to-back birdies on the back nine to take sole possession of the lead before making bogey on the 18th hole to end the day at four-under, in a tie with England's Mel Reid.
The last amateur woman to lead a round at the US Open was Jane Park at Newport Country Club in 2006.
This is Ganne's second US Open appearance after also gaining entry as a 15-year-old two years ago. In that edition, however, she missed the cut. Now, Ganne says she's learned from that experience and has what it takes to stay with the world's best.
"I think the first time is nerve-racking for anybody and meeting your idols and being on the stage for the first time," she told media.
"But the second time around, even the practice rounds, I wasn't as nervous. I felt like I could come here and just play my game instead of soaking that all in."
While Ko has posted one tournament victory and five top-10 finishes in 2021, she is still searching for her first victory at a major championship since 2016.