ATP World Tour Finals: Novak Djokovic bt Kei Nishikori

Djokovic wins the first match of the tournament 6-1, 6-1.

Despite a few scrambles by Nishikori, who eventually managed 3 aces, all of them in the second set, he was unable to overcome the Djokovic juggernaut.

It's about to be a straight sets whitewash of Kei Nishikori. Advantage Djokovic and it's break and match point!

Ripper of a forehand down the line from Nishikori wins him his 1st game of 2nd set! Djokovic leads 2-1 (with a break) & by 1 set #ATPFinals
— IndyCapeSport (@IndyCapeSport) November 15, 2015

Another two aces in the second set! Djokovic is making quick work of the Japanese ace.

This one getting away from Nishikori quickly. Djokovic breaks the Nishikori serve to lead 1-0 in the 2nd set. #ATPFinals
— Steven Sports News (@StevenSportNews) November 15, 2015

Djokovic has been dominant so far with two aces in the first set, with none from Nishikori.

Nishikori fights back! He takes the game for Djokovic, but the World No. 1 is too much for him. He takes the first set 6-1.

Djokovic has taken 3 games in a row now.

And they're off! Early minutes, with Djokovic up 30-0.

Djokovic is the defending champion at the tournament, and recently completed 172 weeks as World No. 1.

Nishikori suffered abdominal pain at the Paris Masters, retiring from the tournament in the third round.

Top seed Novak Djokovic and Japanese ace Nishikori have met 6 times before, with Djokovic taking 4 of those wins.