Berlin (dpa) – Australian Open champion Novak Djokovic of Serbia stays well clear at the top of the men's ATP tennis rankings released Monday. Djokovic has 13,630 points to lead from Spain's Rafael Nadal (10,435), with Roger Federer of Switzerland improving slightly to 8,330 in an unchanged top 10. ATP top 10 as of February 20 (previous ranking in parenthesis): 1. (1) Novak Djokovic, Serbia, 13,630 points 2. (2) Rafael Nadal, Spain, 10,435 3. (3) Roger Federer, Switzerland, 8,330 4. (4) Andy Murray, Britain, 7,150 5. (5) David Ferrer, Spain, 4,595 6. (6) Jo-Wilfried Tsonga, France, 4,410 7. (7) Tomas Berdych, Czech Republic, 3,950 8. (8) Mardy Fish, United States, 2,915 9. (9) Janko Tipsarevic, Serbia, 2,770 10. (10) Juan Martin del Potro, Argentina, 2,705. BM ShortURL: http://goo.gl/Fk6lm Tags: ATP, Djokovic, Ranking, Tennis Section: Sport