Golf-Yang, Choi lead Women's PGA Championship

* Choi cards five-under 66 * Yang five-under with one hole left * Thirty players unable to finish (Updates to end of day) OLYMPIA FIELDS, Illinois, June 29 (Reuters) - Amy Yang had a share of the lead with fellow South Korean Chella Choi when threatening weather halted the first round at the KPMG Women's PGA Championship on Thursday. Yang, twice a major runner-up at the U.S. Women's Open, bogeyed the 17th hole to fall back to five-under and surrender the sole lead moments before lightning prompted the late afternoon suspension. She is among 30 players who will return early on Friday to complete the round at Olympia Fields. On a day of low scoring, Choi birdied four of the final six holes to set the clubhouse pace at five-under 66 as Michelle Wie and Brooke Henderson also made promising starts with 68. Newly-crowned women's world number one Ryu So-yeon, who won the year's first major at the ANA Inspiration, made a smooth start with a tidy 69 in front of a small afternoon gallery that included her mother Cho, the cathedral-like silence on the course broken mainly by an occasional passing train along the line that runs adjacent to the first fairway. Co-leader Choi was particularly pleased with her score after only one practice round, leaning heavily on her father-caddie Ji for advice. "I played just 18 holes before the tournament, so I don't remember every hole," said Choi, winner of one LPGA event. "But I ask my dad, every hole, every shot and my shots were very good today." Not that her father's advice was perfect. "My father missed a couple of shots today but it just happens because wind is every time switching, so very difficult for the caddie," she said. Canadian Henderson also finished strongly with three late birdies, before downplaying her chances of defending the title she won after a playoff with Lydia Ko last year. "Of course, I would love to do it again but it's a different golf course and a different year," she said. "Everything's different but I gave myself a great round today." Former child prodigy Wie continued her recent resurgence, a fine approach to the ninth hole leading to a birdie, which got her back to even par and set her up for a strong back nine. "Yeah, 2016 was a miserable year," said the 27-year-old from Hawaii, who has finished in the top four in her past three starts. "I was sick of playing bad golf, sick of being down and started this year with a really good sense of determination and motivation." Wie also has adopted a most unusual approach to putting, using several different grips, seemingly on a whim. So how many grips does she use? "I don't know," she said. "Don't try to figure it out. I'm like 'this feels right' and I just go with it." (Reporting by Andrew Both; Editing by Ian Chadband / Ian Ransom)