Novak Djokovic v Kei Nishikori
Djokovic and Nishikori square off for the third time in 2014 in London.Getty Images

Defending champion Novak Djokovic meets Kei Nishikori in the first semi-final on day seven at the ATP World Tour Finals at the O2 Arena in London.

Where to Watch

Novak Djokovic v Kei Nishikori is live on BBC Two, Sky Sports HD3 and BBC Radio Five Live Sports Extra from 2pm.

Preview

Despite securing the year-end world No.1 and cruising through to the semi-final with a 3-0 round robin record, Djokovic faces his toughest test to date to reach a third straight final at the World Tour Finals against a player who has had his number in 2014.

Nishikori beat Djokovic at the US Open in four sets in the biggest win of his career and will be hoping to call on similar inspiration in order to continue his fairytale debut at the season-ending tour finals.

The Japan player even has an indoor win over Djokovic to his name back in 2011, no mean feat against the Serbian who is on a 30-match winning streak indoors and who is looking for a third title in a row in London.

The No.1 seed dismantled Nishikori in straight sets and for the loss of just five games on his way to winning the Paris Masters and having not dropped a set on route to the last four appears to be capable of producing a similarly dominant display this time around

Wins over Andy Murray and alternate David Ferrer helped Nishikori comfortably through alongside Roger Federer from Group B but faces and daunting prospect of having to beat the top two players in the world if he is to claim the biggest title of his professional career.

What they said:

Novak Djokovic: "Well, it's obvious that he [Nishikori] is experiencing the best season of his life. He's top five of the world. He's playing some great tennis. He's one of the quickest players around. Deservedly he's in semifinals only on his debut. I'm feeling pretty confident playing now, as well as he. So it's going to be a good, high‑class tennis.

Kei Nishikori: "Novak has been playing amazing this year. I just played him in Paris. He's very, very solid. Good serve, good forehand, backhands. Doesn't have much weakness. I think right now he's the most fit player.

Betting odds (source: William Hill):

Novak Djokovic 1/8 v Kei Nishikori 9/2

Head-to-head record: Djokovic 2-2 Nishikori. Last match Paris Masters (Hard) Djokovic bt Nishikori 6-2 6-3.

Previous meetings at the ATP World Tour Finals: N/A