Spain's Pablo Carreno Busta reached the US Open semi-finals for the first time with a straight-set win over Argentina's Diego Schwartzman.
The 12th seed overcame 25-year-old Schwartzman 6-4 6-4 6-2 in one hour and 58 minutes in New York.
Carreno Busta, 26, is yet to drop a set at the tournament and is the highest-ranked man left in the bottom half of the draw.
He will face the winner of Sam Querrey and Kevin Anderson in the last four.
Querrey and Anderson meet later in the second night session match on Arthur Ashe Stadium.
"Incredible.