Ko's rivals for the the top ranking this week, Korean So Yeon Ryu and Thailand's Ariya Jutanugarn, have shot one under and one over par respectively.
(AP Photo/Steve Helber). Lexi Thompson, left, walks with her caddie Kevin McAlpine to the ninth tee during the first round of the Kingsmill Championship LPGA golf tournament in Williamsburg, Va., Thursday, May 18, 2017.
Thompson's 6-under score matched her second-best round of the season. She started to gain momentum by hitting a birdie on No. 1 (her 10th hole) and put together a stretch of six birdies in seven holes.
Thompson began her round on the back nine and was even at the halfway mark.
The former Kraft Nabisco Championship victor and 2017 runner-up hopped out of a plane for the first time to skydive into Kingsmill Resort in Williamsburg, Va., as part of revealing a charitable partnership with the SEAL Legacy Foundation.
"The second nine was pretty insane", Thompson said. "I hit some great shots and rolled a few good putts, so that definitely helped out my confidence".
Lexi Thompson made a sky-high entrance to the Kingsmill Championship on Wednesday.
"It always helps to see the other players in your group play well", Thompson said about Piller.More news: Four-goal Kane shines as Tottenham hammer Leicester in PL clash
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"A dream come true is all I can say".
After starting 10,000 feet in the air, Thompson dove into her tee time with Navy Seals and the Red Bull Air Force.
"It was an unbelievable experience", Thompson said. The campaign continues through November 11 and raises funds and awareness in support of the SEAL Legacy Foundation, according to its website. "Not only did I get to skydive, but I got to jump with Navy SEALs, who are the most elite members of our military", said the world No. 5. "Words can't describe the feeling". "I don't think I was hitting the ball fantastic, so there is a little bit of improvement to do there". "The girls are playing great, so I know that I need to try and keep up, and to be in contention, I need to make a lot of birdies out there".
The Kiwi has mixed five birdies with a bogey to card an opening round four under 67, to be in a three way tie for fifth at the Kingsmill Championship.
"Obviously, that s a really good start to the week", Ko said. "The greens are rolling phenomenal". I love the course. "Just happy to be under par and looking forward to tomorrow".
Lincicome had five birdies in a bogey-free round.
The top-ranked American on tour, Thompson has yet to win in 2017 but generated the most media attention after an unfortunate four-stroke penalty on Sunday of the ANA Inspiration derailed her chances of a second major title.
"There are some longer holes, some shorter ones where you can play aggressive and a par-5 on which you can get home for two", Ko said.