Atherton teen becomes the youngest in decades to win a U.S. Open match

ATHERTON, Calif. (KGO) -- Catherine Bellis, a 15-year-old Atherton teenager known by many as Cici, became the youngest player to win a U.S. Open match in nearly two decades.

"I went into the match thinking it would be such a great experience, but never thought I would come out on top winning," Bellis said.

And neither did most. The newcomer, a wildcard, competed Tuesday professionally for only her 13th time. Her world ranking was 1,208. Bellis was matched against the tournament's number 12 seed.

It wasn't even supposed to be televised, but as word spread of her impending victory the crowds and the cameras flocked to the young prodigy.

"I'm feeling amazing, I'm still speechless and in shock about that match," Bellis said.

The last 15-year-old to win a U.S. open match was Anna Kournikova back in 1996.

Bellis won the girls 18 and under Junior Nationals to gain a wild card into the competition. She grew up in Hillsborough and now lives in Atherton. Her first coach at three years old, Craig Layton, said he was not surprised she won. He describes her as a sweet, quiet kid off the court, but it's a different story when she's playing.

"On the court she can howl," Layton said. "She can rip her opponent apart."

The teenager honed her craft at the Burlingame Country Club as a kid and a couple of years ago a match was set up against a 30-year-old male pro. She didn't win but showed her fans two things.

"She likes the stage, enjoys that," said Bow Rogers, a family friend. "Number two, you could see her determination and fight."

"It's crazy to think that I'm actually here right now with all these other people. I never thought that I would be practicing or sharing a court with a player that I watch on TV," Bellis said.

The teen is the talk of the town now enjoying her moment in the history books.

Her first-round victory should earn her $60,000, but she's reportedly not going to take it, wanting to keep her amateur status in case she wants to play in college.

ABC News contributed to this report.