Former world number ones Rafael Nadal and Roger Federer are both outside the top four in the men's world rankings for the first time in 13 years.
Spaniard Nadal, 30, is fifth in the latest ATP standings, with 35-year-old Swiss Federer two places lower.
Serbia's Novak Djokovic tops the list, ahead of Briton Andy Murray and Federer's compatriot Stan Wawrinka, with Japan's Kei Nishikori in fourth.
Briton Johanna Konta is in the women's top 10 for the first time.
The 25-year-old climbs to ninth after reaching the final of the China Open, in which she was beaten by Agnieszka Radwanska.