Coco Gauff, 19, won her first Grand Slam title after defeating Belarusian player Aryna Sabalenka in the final of the U.S. Open on Saturday. She is the youngest American to win the title since Serena Williams in 1999.

“It’s still crazy,” she told NBC. “Even last night, I was telling myself, ‘You’re a Grand Slam champion,’ and it doesn’t feel real at all.”

Gauff fell to the ground in disbelief after her win. 

“I feel like it hit all at once because I didn’t want to tell myself it was match point on the match points, I didn’t want to start shaking. So when it happened and like, finally it was over, my previous matches (have) taken me like six, seven match points to win, and that was on the first one, so I was a little bit shocked, and I couldn’t breathe either,” Gauff told the news outlet.

“I would think in the past it would be more relief than joy, but I think with all the growth and maturity I’ve done, it’s definitely more joy than relief.”

Gauff took to TikTok to share the win with her followers. She filmed herself from the court, trophy in hand, bobbing her head and smiling to “All I Do Is Win” by DJ Khaled.

She posted another video from outside Arthur Ash Stadium on the social media platform. Gauff lipsynched the lyrics to Nicki Minaj and Ice Spice’s viral hit “Barbie World” while holding her trophy.

“This barbie is the us open champion,” she captioned the post.

@cocogauffthis barbie is the us open champion 💞♬ Barbie World – &lt3

She posted two other clips with “Empire State of Mind” by JAY-Z and Alicia Keys as a sound. Again, she showed the trophy to the camera as photographers captured the scene.

Gauff also posted a montage of scenes after her win, including a clip in which President Joe Biden congratulates her on being the Grand Slam winner.

Gauff shared she immediately called her family after her win. She told NBC her father wore a shirt with the word “Imagine” as he watched her play the final.

“He just said he bought it at the beginning of the tournament. He said that he had an image that I was going to go make it to the final, and he was going to wear that shirt if I did,” Gauff said. “And I think just imagine, just imagine that your dreams can come true, and you just have to keep working for it.”

Gauff’s mother said her daughter’s success can be attributed to her talent, dedication and self-discipline.

“Coco is a very dedicated, self-disciplined person. She was very gifted as a child. She always strived to do her best. It comes from within her,” Candi Gauff told NBC.