Mexico's Job Castillo delighted the home crowd by defeating Brazil's Ygor Coelho, the men's defending champion and top seed at the Pan American Individual Badminton Championships in Aquascalientes.
Castillo had started the day with a 21-13 10-21 21-7 victory over compatriot Luis Armando Montoya Navarro at Centro Olímpico Juan Pablo Duarte.
He then defeated Coelho 23-21, 18-21, 21-15 to reach the semi-finals.
Castillo's next opponent will be Guatemala's Kevin Cordon, who had beaten Howard Shu of the United States 21-16, 21-11.
Cuba's Osleni Guerrero and Canada's Jason Anthony Ho-shue make up the other semi-final.
In the women's competition, top seed and defending champion Michelle Li set up a clash against Crystal Pan of the United States.
She eased past Ecuador's Maria Delia Zambrano 21-9, 21-15 and Nairoby Abigail Jimenez of the Dominican Republic 21-15 21-7.
The remaining semi-final will be between Canada's Brittany Tam and Jennie Gai of the United States.