Hannah O'Sullivan won the U.S. Women's Amateur on Sunday, beating Sierra Brooks 3 and 2 in the 36-hole final at Portland Golf Club.

The 17-year-old O'Sullivan, from Chandler, Arizona, took the lead with a birdie on the par-4 30th, added birdie wins on the par-4 32nd and par-5 33rd and ended the match with a two-putt par for a halve on the par-4 34th.

O'Sullivan won the Symetra Tour's Gateway Classic in February at 16 to become the youngest winner in the history of the professional circuit. In May, she teamed with Robynn Ree to finish second in the inaugural U.S. Women's Amateur Four-Ball at Bandon Dunes.

The 17-year-old Brooks is from Sorrento, Florida.

Both players earned exemptions for the 2016 U.S. Women's Open.