With 16,790 points, Serbian Novak Djokovic held on to his top rank in the Association of Tennis Professionals (ATP) world singles rankings released on Monday.Spain’s David Ferrer fell to eighth place following his elimination from the Rio Open quarterfinals by Austrian Dominic Thiem. Japan’s Kei Nishikori rose one spot to sixth while Czech Tomas Berdych advanced to seventh.Serena maintains lead in WTA rankingsUnited States player Serena Williams kept her lead in the Women’s Tennis Association (WTA) rankings with 9,245 points while Polish Agnieszka Radwanska went up to third.The Pole came in third behind German Angelique Kerber after the defeat of Romanian Simona Halep, who dropped to fourth in Dubai. Swiss Belinda Bencic jumped to seventh while Italian Flavia Pennetta went down to ninth.In this week’s rankings, Italian Roberta Vinci joined the top-10 list.Men’s top-101. Novak Djokovic (Serbia) 16,790 points2. Andy Murray (Scotland) 8,8553. Roger Federer (Switzerland) 8,7954. Stan Wawrinka (Switzerland) 5,8705. Rafael Nadal (Spain) 4,8806. Kei Nishikori (Japan) 4,2357. Tomas Berdych (Czech) 3,9908. David Ferrer (Spain) 3,9159. Jo-Wilfried Tsonga (France) 2,95010. Richard Gasquet (France) 2,760.Women’s top 101. Serena Williams (USA) 9,245 points2. Angelique Kerber (Germany) 5,7003. Agnieszka Radwanska (Poland) 5,2104. Simona Halep (Romania) 4,7455. Garbie Muguruza (Spain) 4,6426. Maria Sharapova (Russia) 3,6727. Belinda Bencic (Switzerland) 3,5058. Petra Kvitova (Czech) 3,4789. Flavia Pennetta (Italy) 3,42210. Roberta Vinci (Italy) 3,325.