"Nobody else saw it in the gallery or anything in the gallery because they weren't at the hole. So I was like, oh dang, they should have been there!" said Cathrea.
It didn't take long, though, for word to spread. Soon after, everyone wanted to catch a glimpse of this golf phenom.
Some people wait their whole lives for a hole in one, but this is Casie's third. Her first was when she was only 9 years old, and her second was when she was 11.
Cathrea is not the youngest player ever to qualify for an LPGA event. Michelle Wie was 12. Still, it's an impressive feat. Cathrea thought she wouldn't reach this milestone until much later in life.
"I thought I'd be through high school and college by now. Being 13 that's pretty cool," said Cathrea.
Cathrea started playing competitively when she was 7. She picked up the sport when she was 5 after tagging along with her dad to his golf lessons.
When asked who was more nervous Cathrea's father, Harry Cathrea, said "Me. I was looking for some place to throw up behind a tree somewhere. It's just amazing. You work so hard to get something and then you get there and it's like 'Oh, oh. What do you do with it now?'"
For now, Cathrea just wants to make the cut. She ended the day two over. Then at some point in her future, she would like to be a regular on tour.
When asked what she thought she would need to work on to get to that point, she said, "Everything. I'm hitting the ball really long right now, but my chipping needs to get better."
But first things first, when this tournament's over, Cathrea knows there's a biology test she needs to make up.