Romania's Simona Halep maintained the No. 1 spot of the Women's Tennis Association rankings released on Monday, ahead of Denmark's Caroline Wozniacki.
Petra Kvitova of the Czech Republic and Elina Svitolina of Ukraine climbed one spot up to fourth and fifth, respectively, reports Efe.
Japan's Naomi Osaka jumped two positions to the sixth, pushing Caroline Garcia of France four places down to the eighth.
Further down the rankings, Puerto Rican Monica Puig pushed up nine spots to be ranked 42nd, after reaching Wuhan Open quarterfinals.
Earlier, Halep lost the first set 6-1 to Tunisia's Ons Jabeur before retiring with a back injury that she also had problems with at last week's Wuhan Open.
It's the fourth straight loss for the defending French Open champion.
Third-seeded Angelique Kerber of Germany cruised past Kristina Mladenovic 6-2, 6-2 to reach the second round. The Wimbledon champion broke Mladenovic four times to extend her perfect record in opening-round matches at Beijing to nine.
Defending champion Caroline Garcia of France survived an early scare against Chinese wildcard Wang Yafan to win 7-6 (10), 6-7 (4), 6-3.
Americans Madison Keys and Sloane Stephens both won their matches to advance, while CoCo Vandeweghe was beaten by Slovenian qualifier Polona Hercog 6-2, 6-1.
Laura Siegemund defeated No. 13 Daria Kasatkina 6-3, 4-2 after Kasatkina retired with gastrointestinal illness.
Timea Babos, Zheng Saisai, Lesla Tsurenko, Dominika Cibulkova and Kirsten Flipkens also advanced.
The current WTA rankings and point scores are as follows:
1. Simona Halep (Romania) 8,061 Points
2. Caroline Wozniacki (Denmark) 5,610
3. Angelique Kerber (Germany) 5,345
4. Petra Kvitova (Czech Republic) 4,635
5. Elina Svitolina (Ukraine) 4,555
6. Naomi Osaka (Japan) 4,390
7. Karolina Pliskova (Czech Republic) 4,345
8. Caroline Garcia (France) 3,925
9. Sloane Stephens (USA) 3,912
10. Julia Goerges (Germany) 3,730
(With Agency Inputs)
