New York (AFP) - Fifteen-year-old CiCi Bellis caused the biggest upset of the US Open on Tuesday when she knocked out Australian Open runner-up Dominika Cibulkova, the 12th seed -- but it cost her $60,000.
Bellis, the world 1,208, defeated the Slovakian 6-1, 4-6, 6-4 to become the youngest player to win a match at the US Open since Anna Kournikova in 1996.
But with the home-schooled Californian looking to the future and a college education, she was unable to claim the $60,420 (45,880 euros) prize money guaranteed for reaching the second round which would have contravened her amateur status.
"I think 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," said the girl from the wine-growing Napa Valley in northern California.
"I don't really think about it (the prize money). I mean, I try to just focus on the tennis rather than anything else, especially thinking about something after the match, like what's on the line for the match, so..."
Playing just her 13th pro-level match, the American teenager was awarded a wildcard into the US Open by winning the US under-18 championships.
Bellis, who learned how to play tennis at her parents' country club, was making her WTA Tour debut and before Tuesday had never met a player ranked inside the top 100.
But her win, noisily supported by friends on Court 6, some of whom had even posted the hashtag #takedownCibulkova in the run-up to the match, made her an instant celebrity at Flushing Meadows.
Bellis was christened Catherine but is known as CiCi after she contracted her first two names.
"So Catherine, my middle name is Cartan. So I just decided CiCi," she said helpfully.
- You have to believe -
Her victory on Tuesday also presented a tidy opposite -- the youngest player in the draw against the shortest with the Slovakian sizing up at a delicate 5ft 3ins (1.61m).
"It was the number one thing that I had to do today. That's what my coach told me before the match also. Just go out there and believe that you can win," said Bellis.
"I mean, if you play well, you can if you believe in it. If you don't believe, there's one option. If you do believe, there's two options. You can either believe and lose or believe and win, but if you don't believe you're going to lose anyway," she explained in a fog of teenage logic.
Cibulkova, a former top 10 player with four career titles and over $6 million in earnings, admitted she may have underestimated her opponent.
"It's not easy to go out on court and play the first round against somebody who has nothing to lose," she said.
"I didn't expect her to play so aggressive. I thought she was a player who just puts the ball back and runs around. The first set went so fast."
Bellis now goes on to face Kazakhstan's Zarina Diyas for a place in the last 32.