“For the first time in a while, my nerves really got the better of me, and it kind of became a little bit paralyzing,” Keys said after the match. “I felt like I was just slow. I wasn’t seeing things the way that I wanted to, which I feel like resulted in a lot of bad decisions and lazy footwork.”

Madison Keys admitted nerves "paralyzed" her in New York as she suffered an unexpected US Open first-round defeat to unseeded Renata Zarazua.

American Madison Keys couldn't overcome unforced errors and double faults as Renata Zarazua made Mexican women's tennis history at the U.S. Open.

Madison Keys struggled to find any rhythm as her quest for a hardcourt Grand Slam double went up in flames after a defeat to Renata Zarazua in the first round of the U.S. Open on Monday.

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.