Jankovic will now meet Clijsters, above.

STANFORD, California -- American Shenay Perry shocked fifth seed Daniela Hantuchova 6-2 0-6 6-3 in the first round of Bank of the West Classic in California on Tuesday.

Continuing the momentum she gained in reaching the fourth round at Wimbledon, the 22-year-old mixed powerful serves with a creative baseline attack to confuse the Slovak.

Earlier, Jelena Jankovic beat Lilia Osterloh 7-5 6-3 to earn a match against world No. 2 Kim Clijsters.

The 49th-ranked Perry was forced to qualify for the tournament, but said winning three matches in the preliminary rounds gave her confidence.

"This isn't the same feeling as reaching the second week of Wimbledon, but it's great to beat someone who has been a top 10 player," Perry told reporters.

"I didn't feel much pressure."

Jankovic, coming off her best finish -- also reaching the fourth round at Wimbledon -- at a Grand Slam event, did not enjoy the searing Californian heatwave.

"It's the same for both players but it's still hard to get used to," Jankovic said. "I wasn't happy with the way I played but I'm glad I didn't have to stay out in the heat."

After a sluggish first set, the 27th-ranked Jankovic delivered four aces and won 67 percent of her first serve points in the second set to finish the match in 1:22.

Jankovic has lost all three of her matches with Clijsters, including in the quarterfinal of the 2002 Bank of the West.

"I need to improve on my serve and to cut down on my errors," Jankovic said. "I just have to be aggressive."

Sixth-seeded Ai Sugiyama defeated Kveta Peschke 6-3 6-4 and Samantha Stosur topped qualifier Olga Savchuk 6-1 6-3 in other first-round matches.

CNN.com gives you the latest stories and video from the around the world, with in-depth coverage of U.S. news, politics, entertainment, health, crime, tech and more.

CNN.com gives you the latest stories and video from the around the world, with in-depth coverage of U.S. news, politics, entertainment, health, crime, tech and more.