is a Serbian professional tennis player who achieved a career-high singles ranking of world No. 26 on 23 April 2018. He made his ATP World Tour debut at the 2009 Serbia Open, losing in the first round. His best individual result has been a Masters 1000 final. He played a Davis Cup semifinal with the Serbian national team. He holds ATP main-draw victories over former or current top-10 players such as Novak Djokovic, Dominic Thiem, Stan Wawrinka, Daniil Medvedev, Tomáš Berdych, Jo-Wilfried Tsonga, Gilles Simon, Fernando Verdasco, David Goffin (twice), Marcos Baghdatis, John Isner, Fabio Fognini (twice) and Pablo Carreño Busta and has a victory in a Masters qualifying round over former top-5 player Gastón Gaudio.