Desiree Linden is the first American to win the women's division of the Boston Marathon since 1985.
Linden ran 26.2 miles in 2 hours, 39 minutes, 54 seconds, through the wind, rain and 38-degree weather.
Linden is a two-time Olympian and placed second in the 2011 Boston Marathon.
She took the lead from Mamitu Daska toward the last part of the race and created a lead so wide that she ran the last 4 miles by herself.
When asked how she felt about winning, Linden said, "I don't have the right words."
Yuki Kawauchi finished first for the men's division.
This year's marathon was the fifth anniversary of the Boston Marathon bombing that killed three and wounded hundreds more.
Additional reporting from Newsy affiliate CNN.