Kei Nishikori keen to achieve career-high ranking

Kei Nishikori has admitted that he is keen to break new ground in the world rankings with a good performance at the ATP World Tour Finals.

The Japanese player can potentially end 2016 at world number three if he outperforms both Milos Raonic and Stanislas Wawrinka in London, and he took the first step to achieving that by easing past Wawrinka in 67 minutes on Monday afternoon.

After the match, the 26-year-old said: "That's my goal for this week.

"Try to win a lot of matches and reach number four or number three. I see the opportunity to go up the ranking."

Nishikori will face either Andy Murray or Marin Cilic on Wednesday as he looks to qualify for the semi-finals.