ATP Finals: Djokovic shows class to beat Isner in straight sets

Novak Djokovic showed why he is the world No 1 by beating John Isner 6-4, 6-3 to get his ATP Finals off to a winning start.

Djokovic was in top form and only gave away six points on serve throughout the entire match as he wrapped up the win in one hour and 13 minutes.

The Serbian was playing the lowest ranked player in the competition but Isner still put in a strong performance himself with his monstrous serve.

Djokovic was able to break the towering-American on three occasions through his notorious defensive work.

"The match was great. I managed to have three breaks of serve which is sometimes mission impossible," Djokovic said.

Djokovic was in top form and only gave away six points on serve throughout the entire match as he wrapped up the win in one hour and 13 minutes.

The Serbian was playing the lowest ranked player in the competition but Isner still put in a strong performance himself with his monstrous serve.

Djokovic was able to break the towering-American on three occasions through his notorious defensive work.

"I just managed to be at the right place at the right time.

"I held my serve well and backed it up well from the baseline. From the back of the court I was solid.

"I missed playing this tournament last year because of injury and I kind of enjoyed the time off, but I also missed playing in this arena.

"This is one of the biggest stages in the world for tennis and I am glad to be back."