US teenager Yealimi Noh fired eight birdies in an eight-under par 64 on Saturday to take a three-shot lead over Hannah Green after three rounds of the LPGA Portland Classic.
Noh, who made the field through Monday qualifying, posted the low round of the day at Columbia Edgewater Country Club in Oregon for a 19-under par total of 197.
"I was hoping for a good week, but to be in contention, I'm really excited," said Noh, who turned professional in January at age 17.
"Yesterday, too, I was just like, I couldn't really sleep. I was excited to come out and try to move on moving day."
"You could easily be on the wrong side of the pin, but I think just with it becoming a bit firmer and a little bit of wind made a huge difference today."
But Henderson added, "It's the opportunity of a lifetime, and you can make it easier on yourself if you can go out and play one round well, as opposed to going to Q-School. If you can capitalize, it changes your whole life."