The first in Serbian tennis history to be ranked World No 1 and among the greatest tennis players of all-time, Novak Djokovic celebrates his 33rd birthday today. Djokovic is a proud owner of 17 Grand Slam titles and the only man, in the open era, to win a major title in three different decades. From dreaming to become a tennis player in a war-torn Yugoslavia to ruling the tennis universe, Djokovic has certainly written his name in tennis folklore.