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.

Monday's match marked just the second time Keys and Zarazúa faced off. Keys won the first encounter, beating Zarazúa at the 2024 French Open. With her win Monday, Zarazúa evened the their head-to-head record.

After 89 unforced errors, including 14 double-faults, the sixth-seeded American was gone from Flushing Meadows with a loss to 82nd-ranked Renata Zarazua.