Australian Open semi-finalist Kim Clijsters replaced Lindsay Davenport at the top of the Women's Tennis Association (WTA) world rankings on Monday.
Belgian Clijsters returned to the number one position for the first time since 2003, one place above Australian Open champion Amelie Mauresmo with American Davenport slipping to third.
The 26-year-old Frenchwoman rose one spot to second after ending her long wait for a first Grand Slam title by beating Belgian Justine Henin-Hardenne in the final.
Henin-Hardenne, who pulled out of the final in the second set due to stomach illness, moved up one place to fifth, while last year's Australian Open champion Serena Williams dropped 24 places to 39th after losing in the third round in Melbourne.
Former world number one Martina Hingis of Switzerland climbed 232 places to number 117 after reaching the quarter-finals in her first Grand Slam event since retiring though injury in 2002.