American teenager Coco Gauff reached her first US Open singles final by beating Karolina Muchova in a semi-final disrupted by protesters.
Gauff, 19, wrapped up a 6-4 7-5 win over Czech 10th seed Muchova when the pair resumed after a 49-minute delay.
Gauff could not convert a match point when serving at 5-4, but broke Muchova to seal victory after winning a 40-shot rally to create the sixth opportunity.
She will face second seed Aryna Sabalenka in Saturday's final.
Australian Open champion Sabalenka, who will become the new world number one after the tournament, dug deep to beat Madison Keys 0-6 7-6 (7-1) 7-6 (10-5) and prevent an all-American showpiece in New York.