Johannesburg - South Africa's Raven Klaasen has reached his highest ever doubles ranking while singles player Kevin Anderson dropped one spot on Monday when the ATP rankings were released.
Klaasen - who reached the final of the men's doubles at the Australian Open with American partner Eric Butorac earlier this year - moved up four places to 26th on the rankings.
Anderson dropped one place to 19th but remained among the top-20 players in the world.
The country's top-ranked women's player, Chanelle Scheepers, climbed one spot to 77 in the latest women's world tennis rankings.
Lucas Sithole held onto the second spot in the men's singles quads division for yet another week, a position he had held since early September.
He moved up one place in the quads doubles rankings to seventh.