Danielle Kang had a 4-up lead after 18 holes and beat out Thailand's Moriya Jutanugarn 6 and 5 Sunday with a par on the par-4 13th at Rhode Island Country Club.
Kang won in 2010 at Charlotte Country Club in North Carolina. Kelli Kuehne was the last player to win two straight years, accomplishing the feat in 1995-96.
The 17-year-old Jutanugarn was the low amateur last month in the U.S. Women's Open.
The Associated Press contributed to this report.