MIAMI, March 23 — Sebastian Korda stared down Carlos Alcaraz yesterday, sending the world number one crashing out of the Miami Open third round 6-3, 5-7, 6-4.

Korda, ranked 36th in the world, notched his first victory over a world number one, sending Alcaraz to his second straight early exit in Miami following defeat to 55th-ranked Belgian David Goffin in the second round last year.