New York — Madison Keys, the Australian Open champion, faced a surprising defeat in the first round of the U.S. Open on Monday. She lost to Mexico's Renata Zarazua with a score of 6-7 (10), 7-6 (3), 7-5. Keys, seeded sixth, struggled throughout the match, committing 89 unforced errors, including 14 double faults. Zarazua, ranked 82nd, needed only eight winners to secure the biggest victory of her career.

This match marked a significant moment for Zarazua, who had previously lost in the first or second round in all eight of her Grand Slam appearances. Keys, who won her first major title in January by defeating Aryna Sabalenka, had a strong history at the U.S. Open, having reached the final in 2017 and the semifinals in 2018 and 2023.

During the match, Keys appeared to struggle with her left thigh heavily taped. Zarazua, standing at 5-foot-3, expressed her awe at playing in Arthur Ashe Stadium, the largest venue in Grand Slam tennis, which can hold nearly 24,000 spectators. "I’m a little bit small in height, so coming in here, it was like: 'Oh, my God. This is huge,'" Zarazua said. She added, "When I retire, I’m going to be really happy about it, so I was like, ‘Just enjoy it.’”

The match lasted 3 hours and 10 minutes, filled with tension as Zarazua struggled to close out sets. She led 4-2 in the first set and had five opportunities to win it but could not convert. Keys eventually took the first set after three set points. In the second set, Zarazua fell behind 3-0 but rallied to win five consecutive games, only to lose the set in a tiebreaker.

In the deciding set, Zarazua served for the match at 5-3 but was broken by Keys, who then leveled the score at 5-all. However, Zarazua regained her composure and won the final two games to clinch the match.

While Keys was one of 25 American players in the women's singles draw, Zarazua was the only representative from Mexico. "It’s a country that we don’t have many tennis players, as you can see," Zarazua noted. "We just try to give our best. But definitely, I could hear some Mexicans cheering, so that was very nice."

In other matches on Monday, Brazilian teenager João Fonseca won his U.S. Open debut, defeating Miomir Kecmanovic. Eighteen-year-old Canadian Vicky Mboko was eliminated by Barbora Krejcikova, while two-time Wimbledon champion Petra Kvitova played her final match before retirement, losing to Diane Parry. Later in the day, Frances Tiafoe, Venus Williams, and Carlos Alcaraz were scheduled to compete.