|US Women's Open second-round leaderboard|
|-7 A Yang (Kor); -4 S Lewis (US), S Oyama (Jap); -3 M Alex (US); -2 R Yoshiba (Jap), I Gee Chun (Kor), M Pressel (US), I Park (Kor), K Webb (Aus), J Park (US). Selected others: +2 L Davies (Eng); +3 C Hull (Eng).|
Amy Yang established a three-shot lead at the US Women's Open with a second-round 66 in Pennsylvania on Friday.
The South Korean 25-year-old hit five birdies and a bogey to move to seven under par, with American Stacy Lewis and Japan's Shiho Oyama a shot behind.
Oyama also carded 66, with six birdies and two bogeys, while last year's runner-up Lewis made 67.
Dame Laura Davies is two over par in joint 32nd, while fellow Briton Charley Hull is three over in joint 44th.
Sweden's Pernilla Lindberg was the highest-placed European in joint 12th at level par, the same score as defending champion Michelle Wie of the United States.
Should Yang maintain her lead at the end of Sunday's final round, victory would be her first at the US Open after four top-10 finishes in the last five years.