Johannesburg: World's top tennis stars Rafael Nadal and Serena Williams have maintained their lead at the top of the latest ATP and the WTA rankings.

The Spaniard is followed by Serbia's Novak Djokovic, who has closed the gap from Nadal to 2,230 points after his win at Indian Wells, while Swiss ace Roger Federer has moved up three places from eighth to fifth after losing to Djokovic in California.