She defeated the ninth-seeded Mika Stojsavljevic, Great Britain after the worst turnaround in the semifinal – 6–1, 6–1.
In the final, the 14th-seeded Belgian Jeline Vandromme awaits.
Nilsson has on the way to the final defeated the American Julieta Pareja, world number one on the junior side, in the sixteenth and the eighth-seeded Spaniard Esquiva Banuls in the quarterfinal.
The 17-year-old from Stockholm qualified for the US Open.
She became two years ago the youngest Swede to win a national team match – both on the men's and women's side – when she won in the Billie Jean King Cup, the women's equivalent to the Davis Cup.
