The 15-year-old had continued her impressive form from Wimbledon by reaching her third career main draw for the event, which is regarded as one of the main warm-up tournaments for the US Open.
However, despite the support from a packed home crowd, the teenager was comfortably beaten 6-4 6-2 by Kazakhstan’s Zarina Diyas in the first round.
“Every loss, there’s something I learn from that, so I learned something about myself,” Gauff said after her match.
The American became an overnight sensation at the All England Club earlier this month by becoming the youngest women to reach the last 16 since 1991.
Eyes on doubles
She beat the likes of Venus Williams on her fairytale Wimbledon run which only came to an end at the hands of eventual champion Simona Halep.
Despite her tender age, Gauff impressed with her level of maturity both on and off the court and attracted a global following from her maiden grand slam.
Fans will still be able to watch the youngster compete in Washington this week as she teams up with 17-year-old Catherine McNally in the women’s doubles.
“I’m really happy for the support that I’ve gotten here,” added Gauff. “It was a sad way to finish the singles run, but I’m excited to play doubles.”
Earlier this month, Gauff told CNN Sport she was looking forward to playing in next month’s US Open and believed she had the potential to win the tournament.
“Always dream big and don’t let anyone limit your dreams because the possibilities are endless,” said the world No. 146.