Emma Navarro, ranked 13th in the world, defeated her compatriot and third-ranked Gauff with 6–3, 4–6, 6–3. The match was somewhat of a fiasco for Gauff, with a total of 19 double faults and 60 unforced errors.
It's more of an emotional, mental thing, she says about the many service mistakes.
A mental barrier that I need to overcome. But there are also other things that I need to look at because I never want to lose matches in this way again.
Last year, Gauff was the big sensation in the US Open. At 19 years old, she defeated Belarusian Aryna Sabalenka and thus won her first Grand Slam title in her career. But Sunday's loss means that Serena Williams remains the last woman to successfully defend a US Open title, in 2014.
Navarro also won the previous encounter between the two American women, at Wimbledon in July. She will now face Spain's Paula Badosa in the quarterfinal.
