Indian Wells, CA (SportsNetwork.com) - Former champions Vera Zvonareva and Daniela Hantuchova were both first-round losers Thursday at the $5 million BNP Paribas Open.

Hantuchova, who titled here in 2002 and 2007, rallied to force a third set against Klara Koukalova but wound up on the losing end of a 6-4, 1-6, 6-3, decision.

Slovenian Polona Hercog drilled Zvonareva -- a two-time Grand Slam runner-up -- 6-1, 6-1 on the hardcourts at the Indian Wells Tennis Garden. An on-the- mend Zvonareva captured the Indian Wells title back in 2009.

Taylor Townsend took out Bethanie Mattek-Sands 6-4, 5-7, 7-5 in a matchup of American wildcards in the California desert.

Another American, Lauren Davis, downed Slovak Anna Schmiedlova 6-2, 6-2, while Belgian Yanina Wickmayer defeated Italian Karin Knapp 6-1, 7-5 and Tunisian Ons Jabeur doused Estonian Kaia Kanepi 7-5, 6-2. Wickmayer's second-round opponent will be former world No. 1 Maria Sharapova, while Jabeur will take on former top-ranked star and last week's Kuala Lumpur champ Caroline Wozniacki.

Meanwhile, Chinese Lin Zhu overcame former French Open champion Francesca Schiavone, of Italy, 0-6, 6-3, 6-3 and Italian Roberta Vinci fought back to beat Aussie Jarmila Gajdosova 4-6, 6-1, 6-2.

Also on Day 2, Kazakhstan's Sesil Karatantcheva beat Bulgarian Tsvetana Pironkova 7-5, 6-1; Serb Bojana Jovanovski handled Dutchwoman Kiki Bertens 6-3, 6-4; Russian Yulia Putintseva erased Czech Tereza Smitkova 6-4, 6-4; Ukrainian Lesia Tsurenko dismissed German Annika Beck 6-1, 6-3; and Belgian Kirsten Flipkens bested American Shelby Rogers 6-2, 6-4.

Other first-round winners included: Czech Lucie Hradecka and Americans Christina McHale and Madison Brengle -- all advancing in straight sets.

The top seeds here are world No. 1 Australian and U.S. Open champion Serena Williams, the French Open titlist and Aussie Open runner-up Sharapova, French Open runner-up Simona Halep, and the U.S. Open runner-up Wozniacki. Sharapova is a two-time winner at Indian Wells, while her fellow former No. 1 Wozniacki captured the title in 2011.

The 2001 Indian Wells champ Williams will end her self-imposed exile from this tournament and play here for the first time in 14 years.

At the 2001 BNP Paribas Open, Serena and her older sister Venus were booed by fans who accused them of match fixing when Venus withdrew from a scheduled semifinal match.

The 19-time major titlist Serena will open her stay against Romanian Monica Niculescu.

Flavia Pennetta was last year's surprise Indian Wells champion, after upsetting Agnieszka Radwanska in the final.

The 2015 titlist will earn $900,400.