Top of the order is tennis and the ATP World Tour Finals. The second seed from Serbia, Novak Djokovic, was taking on Japan's Kei Nishikori in the second semi-final of the day. Djokovic is aiming for a record-tying sixth title at the season ending event, but even more importantly, he's trying to get his world number one ranking back. But to do that Djoker must finish ahead of the newly crowned top dog Andy Murray who beat Nishikori in a marathon match to reach the last four.

Novak Djokovic of Serbia returns the ball during the singles semifinal with Kei Nishikori of Japan at the 2016 ATP World Tour Finals at the O2 Arena in London, Britain on Nov. 19, 2016. Djokovic won 2-0. (Xinhua/Han Yan)

Nishikori serving and down 3-0 in the first set, and it's understandable if the Japanese is a bit tired after his loss to Murray, but he provides little fight here.

Djokovic now leads 5-1 as he looks to close out the first frame quickly, but the fifth seed shows signs of life as he drills a backhand down the line.

But Djokovic still won the first set 6-1 and is now up 5-1 once again in the second. And the Serb looks to be in complete control as his exhausted opponent fails to keep up from the baseline while Nole brings up match point.

And the Serb makes short work of Nishikori as a forehand winner seals the deal in just one hour and six minutes while losing only two games which means Djokovic will be fresh for the final on Sunday.

"There you go. You know, I'm really privileged and obviously honoured to be a part of the history tomorrow with Andy. We've known each other for so many years. This is maybe one of the biggest matches, the match tomorrow that we'll ever play against each other, so let's enjoy it," said Djokovic.

"I'm obviously tired. I've played so much tennis the last few months, this week I've played a lot of long matches so I'll just give it my best effort tomorrow, the best of what I have. It's going to be, obviously, tough but I'll give it my best shot," said Murray.

Scot to battle Djokovic for title and World No. 1 ranking

So that was Andy Murray speaking after his epic victory over Milos Raonic in the first semi-final, but I bet you want to see some actual highlights, like this fantastic passing shot from the world number one that caught a bit of the net prompting his reaction.

Raonic won the first set 7-5 and the second goes to a tiebreaker which Murray now leads 5-3. This is the first time in his career that the Canadian Raonic has reached the last four of this event, and the 25 year old smacks a winner to make it 5-4 for the Scot.

Now tied at 5, Murray cannot afford a slip up. If he loses this match, he loses the number one ranking to Djokovic who is already through to the final, but that beautiful volley helps his cause as he goes on to claim the frame.

The decider would be even closer somehow. Raonic serving with the score tied at 3 and the Canadian is really making Murray run from side to side, but eh Scot's efforts pay off when he wires a backhand down the line for an incredible winner.

But Raonic was still able to hold serve in that game and is now looking to put pressure on Andy as he takes a 30-0 lead with a well controlled volley.

It goes to another tiebreaker which Murray now leads 4-3. The world number one nails a forehand to the corner which raonic barely returns, and the Scot puts it away for a two point edge as the crowd goes crazy for their hometown hero.

Raonic would hang on through multiple dramatic comebacks, but Murray now has match point at 10-9. The Candian crushes a forehand but Murray is on it and then Raonic hits the net. Murray wins the incredible encounter in 3 hours and 38 minutes to set a new record for the longest three-setter in the tournament's history. His 23rd straight win means he will next face Djokovic for the title and world number one ranking.