A year ago, Halep was ranked No. 64 and forced to qualify for the Italian Open. She did so and made the semifinals, igniting a stretch in which she closed 2013 by winning the first six titles of her career. She then opened 2014 by reaching the Australian Open quarterfinals (her best result at a Grand Slam tournament), winning the Qatar Open, advancing to the BNP Paribas Open semifinals and getting to the Madrid Open final. She'll be the fourth seed at the French Open, which begins on Sunday.
Azarenka, meanwhile, withdrew from Roland Garros because of a right foot injury that has limited her to three tournaments this year. The former No. 1 hasn't played since an opening-round loss to Lauren Davis at the BNP Paribas Open on March 7.
In other rankings news:
• Jelena Jankovic (now No. 7) and Maria Sharapova (No. 8) switched places.
• Zhang Shuai, a 25-year-old from China, moved up to a career-high No. 34 after making her first Premier-level quarterfinal, in Rome, where she upset Petra Kvitova in the second round. She was No. 43 last week.
• Camila Giorgi also hit a career high, at No. 51. The 22-year-old Italian ended last season at No. 93. She has beaten Maria Sharapova and Dominika Cibulkova this year.