The American started the third round four strokes behind Filipino teenager Yuka Saso, but mastered the course on a day when many of the other contenders struggled.

Thompson birded the par-five 17th to move to seven under for the tournament and holds a one-shot lead over Saso.

The five-under-par round of 66 is tied for the best of the tournament, and is the first not to feature any dropped shots.

Saso, the Asian Games champion, carded a level-par 71, with a bogey on the final hole costing her a share of the 54-hole lead.

American amateur Megha Ganne will be in tomorrow's final grouping along with Saso and Thompson, as she is tied for third place on three under after shooting 72.

Lee Jeong-eun of South Korea, who is often known as "Jeongeun Lee6" and won this event in 2019, is also four shots behind the leader after shooting 73.

Lee made a harmful double bogey on the par-four 5th hole.

Her compatriot Park Inbee, the Olympic champion, also shot 73 and has dropped back to even par.

Thompson has never won the US Women's Open, having first appeared in the tournament as a 12-year-old in 2007.

The 26-year-old has one major to her name, the 2014 ANA Inspiration.