“Honestly, I didn’t feel comfortable at all during the match – even on the match points,” Gauff said. “I know the game [Ostapenko] plays. She has the ability to come back no matter the scoreline, so I was just trying to get every point, put every ball in."
“It’s really tough against her because you can’t really be aggressive, so I was trying my best to be aggressive when I could, and most of the time I was just trying to get the ball deep," she continued. "She’s a tough player and she had a great tournament.”
The victory makes Gauff, 19, the first American teenager to reach the U.S. Open semifinals since Serena Williams in 2001.
"Last year, I lost in the quarterfinal stage, and I wanted to do better this year," Gauff said. "Still have a long way to go, but I'm happy and I'm ready to get back to work for the next one."
In Thursday's (September 7) semifinals, Gauff will either face No. 10 Karolina Muchova of the Czech Republic or No. 30 Sorana Cirstea of Romania. Muchova and Cirstea are scheduled to play Tuesday night.