Hamburg - Rafael Nadal remained comfortably top of an unchanged men's tennis rankings issued on Monday by the ATP. Spain's Nadal leads with 14,470 points, far ahead of former number one Roger Federer of Switzerland (11,020), Serbia's Novak Djokovic (9,010) and Scotland's Andy Murray.

ATP top 10 as of April 13 (previous ranking in parentheses): 1. (1) Rafael Nadal, Spain, 14,470 points 2. (2) Roger Federer, Switzerland, 11,020 3. (3) Novak Djokovic, Serbia, 9,010 4. (4) Andy Murray, Britain, 8,840 5. (7) Juan Martin del Potro, Argentina, 4,790 6. (6) Andy Roddick, United States, 4,340 7. (7) Gilles Simon, France, 4,010 8. (8) Fernando Verdasco, Spain, 3,760 9. (9) Nikolay Davydenko, Russia, 3,735 10. (10) Gael Monfils, France, 3,600