NEW YORK (AP) -- Mallory Burdette opened the summer plotting how she would take pre-med courses to pursue her dream of studying psychiatry.
A few unanticipated wins on the tennis court later, the 21-year-old American is rethinking her plans for her senior year at Stanford.
At her first Grand Slam tournament, Burdette is into the third round. Her next opponent? Maria Sharapova.
''To end up here at the U.S. Open was a huge surprise,'' Burdette said after beating Lucie Hradecka 6-2, 6-4 in the second round Wednesday. ''I never expected that at the beginning of the summer.''
Burdette figured she lost her only chance to qualify for the Open when she squandered a lead in the NCAA singles final in May - the college champion gets an automatic bid. She was aware when she entered USTA Pro Circuit events that she could receive a wild card if she earned enough points. But that wasn't why she signed up.
The 252nd-ranked Burdette was ambivalent about playing professionally after finishing her last college season, and these tournaments were a way to experience the life of a pro athlete. She wasn't sure how she would cope with the travel; she wasn't sure how her body would hold up.
Turns out, she enjoyed the grind just fine. Oh, and as a bonus: She clinched that wild card into the Open.
''That wasn't even on my radar,'' she said. ''So it's been a crazy ride.''
Burdette easily could have faced a top-ranked player in the first round, but she got a favorable draw. She beat 308th-ranked Timea Bacsinszky of Switzerland, who got in on a protected ranking, 6-4, 6-3 in her opener.
Meanwhile, the 69th-ranked Hradecka, a Czech doubles specialist, upset 27th-seeded Anabel Medina Garrigues. Hradecka has never reached the third round at a Grand Slam event.
The caliber of Burdette's opponent now changes dramatically. Her meeting with the third-seeded Sharapova, winner of the career Grand Slam, will most likely be in Arthur Ashe Stadium. Burdette's matches so far have been on Courts 6 and 11.
Sharapova, who defeated Lourdes Dominguez-Lino 6-0, 6-1, said she expects her next match to be one of those rare occasions where she isn't the fan favorite.
''Obviously, she's going to get a lot of home support, which is absolutely normal,'' Sharapova said. ''I've lived in this country since I was 7 years old. I consider this to be my home. But I understand on the other side if the crowd does cheer for her as she's coming in as the underdog.''
Burdette has been in Ashe before - during the National Indoor Intercollegiate Championships at Flushing Meadows, players get a night tour.
''I have only walked out on Ashe with nobody in the stadium,'' Burdette said.
Burdette remembers watching Sharapova win her first Wimbledon title with coach Nick Saviano and discussing how she could emulate her game. Burdette notices how the Russian star keeps to her routines between points to stay focused, and the young American has also done that well this summer to manage all this newfound pressure.
In 2009, Sharapova played another young player from Georgia in the third round at Ashe - and lost to Melanie Oudin.
''I might talk to Melanie a little bit, ask her a few questions just to get the inside scoop,'' Burdette said, smiling.
Burdette, whose two older sisters were also All-America tennis players for the Cardinal, won her first WTA match at the Stanford tournament last month. She always figured she might play some doubles professionally. Until the last few weeks, she considered med school to be more likely in her immediate future than a pro singles career.
A psychology major, Burdette wants to be a psychiatrist. She was looking into programs to complete her pre-med requirements after she graduates.
Now, those plans almost certainly are on hold.
''I think just maturity over the years,'' Burdette said of what's changed. ''It doesn't scare me as much to play pro tennis and to be successful. Just managing myself better out there on the court with my emotions has been huge.''
Burdette would earn at least $65,000 for her third-round run if she wasn't trying to maintain her college eligibility. She joked that since ''I have already checked the amateur box,'' there's no going back. Players have switched status from amateur to pro mid-tournament in the past, but kidding aside, Burdette plans to play her senior season at Stanford. Her coach there, Lele Forood, reached the round of 16 at the 1978 U.S. Open as a player with a win over Virginia Wade.
Burdette was leading teammate Nicole Gibbs in the NCAA final 6-2, 4-1 in the second set but couldn't close out the victory. She was also up 5-2 in the second-set tiebreaker but went on to lose in three sets - seemingly costing her that U.S. Open bid.
Burdette was supposed to play doubles with Gibbs at the Open - the two won the NCAA title together hours after facing off in singles - but Gibbs pulled out because of injury after losing her first-round singles match. They would have taken on the Williams sisters on Wednesday.
Burdette will have to settle for facing Sharapova in singles. The psychology major is fascinated by the champion's mental resolve.
''It's hard out there sometimes. You get outside of yourself and you're worrying about things you can't control,'' Burdette said. ''That's one of the things she does a very good job of. You can tell she's in the zone every time she walks up to play a point. That's amazing, and nobody's perfect when it comes to their mental side. I think that's very interesting.''