Tennis star Novak Djokovic was booed by some sections of the crowd after retiring injured from his Australian Open semifinal against German Alexander Zverev. Djokovic, who was aiming for an all ...

Novak Djokovic turned pro at just 15 years old (2003), winning his first Association of Tennis Professionals title one year later. He nabbed his first ATP Tour title at the 2006 Dutch Open without ...