She has won the Australian Open, and her father Petr Korda is a former tennis pro who is a grand slam event victor. Finishing in a tie for sixth at the ANA Inspiration in April, the 23-year-old is hoping to emulate her younger sibling and become a major champion.
The field will be cut to the low 60 scorers and ties after two rounds.
Ariya was also six under after eight holes, among half the field unable to complete the round following a lightning delay that stretched to almost four hours.
A lack of practice rounds was no problem for Ariya Jutanugarn and Sarah Jane Smith as they joined Lee Jeong-eun in the lead on the opening day at the U.S. Women's Open on Thursday.
She won the Lotte Championship this year and has two previous top 10 finishes in the U.S. Women's Open. "Under par, I'm really happy". If the USGA keeps the course at that length, the field of potential winners is going to shrink and Henderson will be in that group. She has a way to go, but nonetheless took delight at seeing her name atop the leaderboard the entire round. Korean-born Su-Hyun Oh shot 68 and is also 6 under.
"It is our intention to play 72 holes to identify our champion, and to play the ball as it lies", he said.More news: Large Wildfires Prompt Evacuations in Colorado, New Mexico
She had a 29-hole bogey-free streak end with a three-putt on No. 8 - she started on the 10th tee - a rare mistake for her at the midway point.
As Smith put it, it has been a "weird week" for the players.
"It's kind of fun seeing that", she said. She had to win to get her card and she did and she opened up that nine holes, I think, 7-under on the front nine and then led the whole way. Normally a player who uses a mallet-style putter, she wielded a blade, a PING Anser 2, at Kingsmill and will use it again this week. She is still chasing Smith, along with everyone else.
"Coming into the US Women's Open, I always try to play the ball with mud or try to play with wet ground conditions because we've never played lift, clean and place", said the South Korean, twice a victor of the event.
The rain at Alabama's Shoal Creek course gave way to sunshine for the start of the first round. Play only continued for about an hour after the delay.
"The course is playing pretty tough, and some holes pretty long", she said. It just felt really easy. Defending champion Sung Hyun Park shot 76.More news: French Open 2018: Alexander Zverev beats Karen Khachanov in five sets
Reid said she made a decision to play the ball down in the wet conditions Wednesday.
Sitting at 3 under after a 68, Spain's Carlotta Ciganda said she was surprised to see any one at double-digits under par like Smith.
"I would think that they would have to play the ball up", Lexi Thompson said Tuesday.
"I feel like my game's been improving every week because I work so hard with my short game", the Thai said.
Ariya Jutanugaren, of Thailand, fixes the collar of her caddie, Leslier Luark, after finishing her round as the leader during the first round of the U.S. Women's Open golf tournament, Thursday, May 31, 2018, in Shoal Creek, Ala. Ariya Jutanugarn had a late tee time.More news: Canada Joins EU?In Filing WTO Case Against "Illegal" US Tariffs