Novak Djokovic-s return to the world number one spot, just five months after slumping to his lowest ranking in 12 years, leaves little doubt that he is one of the sport-s greats.

The Serb is back on the top of the pile for the first time in two years, at the end of a roller-coaster season for the 14-time major winner. Djokovic, 31, underwent elbow surgery in January and slipped to 22nd in the world after a depressing quarter-final exit at Roland Garros in June, which left him briefly threatening to skip Wimbledon.