Top-seeded Jelena Jankovic loses at La Costa

Reporting from Carlsbad — Melanie Oudin’s bravado comes through when she shouts, “Come on,” after a forehand winner and a fist pump in the direction of her opponent after an unexpected backhand volley.

But then she has trouble hitting a first serve over the net and there is an unhappy yelp and a slap to the forehead.

Oudin, 18, and a U.S. Open quarterfinalist a year ago, lost to second-seeded Samantha Stosur, 6-4, 6-4, Wednesday in the second round of the Mercury Insurance Open and once again Oudin is finding out that it’s a tough world in pro tennis.

It’s a tough world when you’re the world’s second-ranked player too. Jelena Jankovic, who is behind only Serena Williams on the WTA computer, and who is the top-seeded player here, was upset in her second-round match, 7-5, 6-2, by big-hitting Russian Alisa Kleybanova.

Jankovic, who has been struggling with a left ankle injury, had a 4-0 lead in the first set before her accuracy deserted her and at one point she lost eight straight games.

“I had some fear moving,” Jankovic said. “At times I was in doubt, should I run or should I not? I’m still not confident I’m not 100%.”

What Oudin has discovered is that she was able to sneak up on opponents once or twice, or four times as she did at the 2009 U.S. Open, when she energized the tournament by beating four higher-ranked opponents and scrambling to the quarterfinals, fresh-faced, enthusiastic and only 17 years old. Now she is never overlooked.

After reaching her career-high ranking of 31 last April, she came here ranked 45th and with Wednesday’s loss at La Costa she has a pedestrian 17-17 record this season.

Stosur, the 26-year-old Australian who has reached her highest singles ranking ever this year at No. 5, said she understands what Oudin is going through this season.

“Anyone who comes out on tour and has a great year the way she did last year,” Stosur said, “when nobody knew a lot about her, you couldn’t do research before going into matches, everybody takes notice.

“It’s good to have a great first year on the tour, but you’ve got to be able to back it up You can’t stay stagnant. If you do the same things every day, you start losing.”

Oudin is still a work in progress and she admits that. She wants to improve her serve and her backhand. She also thinks that her U.S. Open success has made her someone special to beat.

“Last year I was just some kid starting out and the other players didn’t think much about me,” Oudin said. “Now I feel the target on my back is a lot bigger this year. No one wants to lose to me, so everyone’s bringing their best.”

diane.pucin@latimes.com

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