Australian Open champion Madison Keys was undone by 89 unforced errors and was upset in the first round of the U.S. Open by Mexico’s Renata Zarazua on Monday.

Madison Keys suffered one of the biggest upsets of the 2025 season on Monday at the US Open, losing to Renata Zarazua.

NEW YORK — Australian Open champion Madison Keys is out of the U.S. Open in the first round. Renata Zarazúa, the world No. 82 from Mexico, came from a set and 3-0 down to stun the No. 6 seed 6-7 (10), 7-6 (3), 7-5 in bright sunlight on Arthur Ashe Stadium. Zarazúa also became the first Mexican woman to ever beat a top-10 opponent at the U.S. Open.