Two-time tour winner Lee moved up from a share of 10th spot at Washington’s Sahalee Country Club as she looks to improve on her best-ever finish at a major championship - a tie for sixth at this event in 2014.

Canadian Henderson took a two-shot advantage into the second round, but in difficult conditions, she hit a two-over 73. 

Henderson birdied the third hole to move three shots clear, however, bogeys at the fourth and fifth saw all the 18-year-old's hard work come undone.

Another bogey at the 10th wiped out her advantage and despite going ahead again with a birdie at the 17th, a dropped shot at the 18th cost her the outright lead.

"I was one under through four, I guess, and was feeling pretty good," said Henderson.

"I just - I got a little too aggressive to a couple of pins early, which kind of cost me a couple of bogeys.

"But I just regrouped a little bit and started to hit to the middle of the greens, which helped me score on the back nine.

"I hit a lot of really good putts that just didn't fall.

"But I'm hoping that will change."

World number one Lydia Ko of New Zealand shot a one-under-par 70 to remain in contention to win her third consecutive women's major.

The 19-year-old, who won the ANA Inspiration in April to add to her victory in the Evian Championship last September, is one shot behind Henderson and Lee after two rounds.

Only five players are under par at the halfway stage of the second women's major of the season with Americans Gerina Piller and Brittany Lincicome joining Ko on one under after posting scores of 69 and 70 respectively.

Action is due to continue tomorrow.