US Open 2014: CiCi Bellis, 15, stuns Dominika Cibulkova

Bellis is the youngest player in a Grand Slam draw for nine years

American 15-year-old CiCi Bellis caused a sensational upset as she beat 12th seed Dominika Cibulkova at the US Open.

Bellis, ranked 1,208 in the world, saw off the Australian Open finalist 6-1 4-6 6-4 on a raucous Court Six.

The junior world number two only received a wildcard by winning the US girls' national championships.

She is the youngest winner of a US Open match since Russia's Anna Kournikova, who was 59 days younger when she reached the fourth round in 1996.

At 15 years 152 days old, Bellis is the youngest player to feature in a Grand Slam main draw for over nine years.

She is the youngest player in the draw by two years, had never played at WTA level before - let alone in a Grand Slam - and she has only 12 singles matches on the lower ITF circuit to her name.

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

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

The teenager from California came back from a break down in the final set, fist pumping all the way and urged on by a home crowd that packed into and all around the outside court.

"I had four friends that started some of the chants," said Bellis. "I was like, 'Oh my God!' I loved it. It made me play even better."

Bellis will face Zarina Dyas of Kazakhstan, the world number 48, in the second round, but she cannot collect the US$60,420 (£36,518) prize money on offer as she is an amateur.

"I don't really think about it," she said. "I try to just focus on the tennis rather than anything else.

"I'm definitely going to stay an amateur right now to keep my options open for college, in case an injury or something happens. But I'd love to be a pro one day."