Johannesburg - Kevin Anderson climbed to a career-best rating in the latest ATP men's world tennis rankings released on Monday.
Anderson rose two places to 25th, improving his previous best ranking of 26th.
The South Africa men's No 1 reached the third round of the Rome Masters last week, where he was eliminated by world No 6 Tomas Berdych of the Czech Republic.
In the second round, he had defeated Croatian Marin Cilic, the world No 13.
South Africa's top women's player, Chanelle Scheepers, dropped four places to 61st in the WTA women's rankings.
Scheepers was eliminated in the qualifying rounds in Rome.
ATP top 10 as of May 20 (previous ranking in parenthesis):
1. (1) Novak Djokovic, Serbia, 12 310 points
2. (2) Andy Murray, Britain, 8 670
3. (3) Roger Federer , Switzerland, 8 000
4. (5) Rafael Nadal, Spain, 6 895
5. (4) David Ferrer, Spain, 6 740
6. (6) Tomas Berdych, Czech Republic, 4 700
7. (7) Juan Martin del Potro , Argentina, 4 320
8. (8) Jo-Wilfried Tsonga, France, 3 795
9. (9) Richard Gasquet, France, 3 090
10. (11) Janko Tipsarevic, Serbia, 2 640
Other:
25. (27) Kevin Anderson, South Africa, 1 420