Just around the time when Rafael Nadal and Roger Federer were dominating the ATP Tour, out of nowhere, a Serbian superstar started showing a lot of promise. In 2003, Djokovic started playing professionally, and in 2004, he played his first tour-level tournament at the 2004 Croatia Open in Umag.
It took only a few years before the talented Serb showed that he was there to challenge the two dominant players, who had won a combined 15 Grand Slam titles until 2008. And it was in that year, 2008, when Djokovic won his first Grand Slam title, beating Roger Federer in the 2008 Australian Open semifinals and subsequently winning against Jo-Wilfried Tsonga in the championship match.
It took the Serbian only a few years before he showed that he would really challenge the Spanish-Swiss duo, and it was in 2011 when he finally established himself as a member of what we now know as the Big Three.
In 2011, Djokovic added his second Grand Slam title at the Australian Open, but in the same year, he went on to win Wimbledon and the US Open, climbing to the world no. 1 spot in the ATP Rankings along the title-paved way.
In the following years, Djokovic tasted a lot of success, winning a few more Australian Open, Wimbledon, and US Open titles, but it wasn't until 2016 that he finally managed to break Rafael Nadal's dominance at the Roland Garros to complete a Career Grand Slam.
