NEW YORK, NY, USA - Colombian teenager Maria Camila Osorio Serrano ended her junior career in spectacular style, winning the US Open girl's singles title over American qualifier Alexandra Yepifanova, 6-1, 6-0.

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"It's unreal," the gregarious youngster said during her post-match press conference. "Like, it's been a really great week for me. I'm just so happy and thankful for this. I'm blessed, and I can't believe I won."

Osorio Serrano, made her WTA breakthrough earlier this year by reaching the Claro Open Colsanitas quarterfinals - falling to eventual champion Amanda Anisimova in three sets - and had to survive two matches in one day on Saturday but recovered well to defeat Yepifanova in just 48 minutes on Court 17.

"When I finished the matches yesterday, I was, like, 'No, right now I'm feeling good. I was just focused on today and my match.'

"Every time I go to play a final, I just want to win. I will just focus on win, and not just win, but in every point, and give my best on the court. That's what I did."

Osorio Serrano cut a serious figure on court, striking five aces - including one on championship point - but dissolved into giggles at the mention of idol Roger Federer, whom she sought out for a selfie twice before at Grand Slam tournaments.

"If he's watching this, This is for you, too," she laughed. "You're my inspiration. I love you so much.

"I hope he can say something to me. Just like, 'Hi.' It's okay for me. Just 'hi' would be fine."

The No.4 seed will return home after the tournament, but will return to the United States later this fall to play ITF Pro Circuit events, with the goal of making the qualifying draw for next year's Australian Open.

"I won a tournament, a Grand Slam, so I can do it maybe in pros.

"I feel like I'm getting closer to what I want. My goal is being No.1 in the world, but in pros, so this is just the beginning. I have a lot of things to work and focus on."

In the doubles final, Oksana Selekhmeteva - who led Osorio Serrano 3-0 in their singles semifinal on Saturday night - partnered Kamilla Bartone to win their first Grand Slam title, defeating the all-French duo of Aubane Droguet and Selena Janicikevic, 7-5, 7-6(6).

"We’re actually so happy to win," said Bartone, a 17-year-old Latvian who made her WTA debut at her home tournament in Jurmala this summer. "We were so nervous before the match. We won against this team at the French Open, but the finals here is totally different. It’s a different surface…"

"...and more pressure, of course," added Selekhmeteva.

"Different emotions. So, we were just trying to keep it up, to be strong, always support each other."

Where Osorio Serrano idolized Federer, Selekhmeteva was debating whether to stay for the men's final, where idol Rafael Nadal was set to face fellow Russian Daniil Medvedev.

"We have shopping time, actually," Bartone reminded her partner to laughter from the press room.

"It’s our last day here," said Selekhmeteva, checking the time on her phone. "I really want, because Medvedev is from Russia and Nadal is my idol. So I’m like, ‘Ok guys, just play, and I will go shopping and it doesn’t matter who wins.'"