Romania's Simona Halep continued her recent surge in the rankings on Monday, climbing to No. 5 in the world, a new career best, after reaching the Indian Wells semifinals.

Also moving up two spots is Jelena Jankovic, who has reached No. 6, her highest mark since 2010. Surprising Indian Wells champion Flavia Pennetta surged nine spots to No. 12. Pennetta who recently turned 32, is seeking to return to the Top 10 after peaking at No. 10 in August 2009.

Maria Sharapova and Angelique Kerber were headed in the other direction, with Sharapova falling two spots to No. 7 and Kerber three places to No. 9.

The top four players: Serena Williams, Na Lia, Agnieszka Radwanska and Victoria Azarenka remained in the same spots. Taking a huge plunge in the Top 20 was former No. 1 Caroline Wozniacki, who slid six spots to No. 18. It's the lowest she's been since just before the 2008 US Open.