Indian Wells, CA (SportsNetwork.com) - Former world No. 1 and former champion Jelena Jankovic was an easy quarterfinal winner Thursday at the $5.3 million BNP Paribas Open.

The 18th-seeded Serb was flattening Lesia Tsurenko, 6-1, 4-1, when the Ukrainian, who tweaked her ankle badly during her upset of Eugenie Bouchard on Tuesday, retired on Day 9 at Indian Wells Tennis Garden.

The 30-year-old Jankovic, who titled here in 2010, now awaits the winner between 15th-seeded reigning Indian Wells champ Flavia Pennetta and 24th- seeded former Wimbledon runner-up Sabine Lisicki.

Friday's other semifinal will pit world No. 1 and two-time Indian Wells champion Serena Williams against third-seeded 2014 French Open runner-up Simona Halep.

Pennetta upset Agnieszka Radwanska in last year's final in the California desert.

The 33-year-old American great Williams, playing here for the first time in 14 years, was the Indian Wells champ back in 1999 and 2001.