American Lexi Thompson fired a six-under-par 65 on Thursday to grab a one-stroke lead after the opening round of the LPGA Kingsmill Championship at Williamsburg, Virginia.

The 22-year-old US star made a run of five birdies in a row on her second nine of the day to stand one stroke ahead of three compatriots – Gerina Piller, Brittany Lincicome and Angel Yin.

"The second nine was pretty crazy," said Thompson, who arrived on the first tee for Wednesday's pro-am by parachuting out of an airplane. "I hit some great shots and rolled a few good putts, so (it) definitely helps out my confidence."

South Korean-born New Zealander Lydia Ko, trying to hang onto the world No 1 ranking, shared fifth on 67 with Australia's Sarah Jane Smith and Italy's Giulia Molinaro.

Thompson, who started on the back nine, birdied the par-4 11th and made her lone bogey of the round at the par-3 17th.

She answered with a birdie on the first hole, her second nine of the round, then ran off her birdie binge starting at the par-5 third and ending at the par-5 seventh.

Thompson hit 17 of 18 greens in regulation. She only missed hitting the green on No 12.

Thompson is playing in her third tournament since losing a playoff in the ANA Inspiration for being penalised four strokes for a rules violation spotted by a person watching the tournament on television.

Ko posted five birdies and one bogey in the opening round.

"Obviously, that's a really good start to the week," Ko said. "I am just going to try and give myself as many opportunities and I can. I don't think I was hitting the ball fantastic, so there is a little bit of improvement to do there."

Leading first round scores

65 - Lexi Thompson

66 - Gerina Piller, Brittany Lincicome, Angel Yin

67 - Lydia Ko (NZL), Sarah Jane Smith (AUS), Giulia Molinaro (ITA)

68 - Jacqui Concolino, Amelia Lewis, Karine Icher (FRA), Vicky Hurst, Candie Kung (TPE), Moriya Jutanugarn (THA), Minjee Lee (AUS), Su Oh (AUS)

69 - Chun In-Gee (KOR), Feng Shanshan (CHN), Suzann Pettersen (NOR), Austin Ernst, Jessica Korda, Pernilla Lindberg (SWE), Kim Sei-Young (KOR), Lee Mi-Rim (KOR), Lindy Duncan, Ayako Uehara (JPN), Gaby Lopez (MEX), Ally McDonald, Sadena Parks, Hsu Wei-Ling (TPE), Carlota Ciganda (ESP), Nelly Korda, Jenny Shin (KOR), Pavarisa Yoktuan (THA)