Britain's Liam Broady stormed into the US Open boys' singles final with a 6-1 6-1 victory over Kaichi Uchida.
Broady, the 13th seed, needed only 55 minutes to see off his Japanese opponent, who was seeded eighth.
The 18-year-old will play Canadian Filip Peliwo in Sunday's final after the Wimbledon champion beat Uchida's compatriot Yoshihito Nishioka 6-4 6-0.
Another Briton, Oliver Golding, won the boys' title last year, while Andy Murray won it in 2004.
Yorkshire's Kyle Edmund and Portuguese partner Frederico Ferreira Silva beat Australian pair Nick Kyrgios and Jordan Thompson to win the boys' doubles title.
Meanwhile, Samantha Crawford of the United States won the girls' singles final, beating Estonia's Anett Kontaveit 7-5 6-3.