Top seed Andy Murray has been playing scintillating tennis at the ATP World Tour Finals in London, and the world number one's quest to keep the top ranking continues but the Brit has never made the final at the year-end Championships.
Meanwhile, Milos Raonic is in pole position to clinch the world number three ranking as reigning US Open champion Stan Wawrinka is out of the ATP World Tour Finals, and Kei Nishikori will have a tough semifinal test with Novak Djokovic, who is looking to regain the world number one ranking from Murray.
Murray and Raonic will be competing in 2016 for the fifth time, and the world number one has won all five of their meetings this year, and he will be the firm favourite to reach the final in London.
Murray's route to the semifinals
The reigning Wimbledon champion began his campaign on Monday against world number seven and 2014 US Open champion Marin Cilic, and the Croat was victorious in their previous meeting in the final of the Western and Southern Open in Cincinnati, and the Croat snapped Murray's first 22-match winning streak.
The Brit comprehensively defeated Cilic, 6-2, 6-3 in the first Round Robin match in Group John McEnroe, however, Murray had a tougher time in his second group match against Kei Nishikori, and the Japanese number one defeated Murray in a five set battle at the US Open, nonetheless, the top seed gained his revenge but had to recover from a set down to defeat Nishikori, 6-7 (9), 6-4, 6-4 in 3 hours and 20 minutes.
On Friday, Murray defeated this year's US Open champion and fellow three-time Grand Slam champion Stan Wawrinka to top the group with a perfect 3-0 record like Djokovic and ensured that the battle for the year-end world number one ranking would be decided over the weekend.
Raonic's route to the semifinals
Raonic returned to the ATP World Tour Finals for the second time in three years but he was a major doubt before the tournament as he withdrew from the BNP Paribas Masters in Paris in the semifinals, however, those fears were immediately dashed as the Wimbledon finalist defeated debutant Gael Monfils, 6-3, 6-4 in Group Ivan Lendl on Sunday.
The Canadian was up against defending champion and world number two Novak Djokovic on Tuesday, and the world number four played some good tennis against the Serb, unfortunately, it was a familiar story for Raonic as he lost to Djokovic in straight sets, 7-6 (6), 6 (5)
The permutations were simple on Thursday as the winner of the final group match between Raonic and another debutant in eighth seed Dominic Thiem, who reached his first Grand Slam semifinal at the French Open, would qualify in second place behind Djokovic. Raonic's experience got him over the line despite trailing 2-5 in the opening set tiebreak and it was a 7-6 (5), 6-3 victory over the Austrian to keep his hopes of finishing as the world number three for the first time in his career alive.
Murray and Raonic have met on 11 occasions, and the world number one has a commanding 8-3 lead in their head-to-head meetings.
Raonic won their first meeting in the quarterfinals on the clay courts in Barcelona in 2012, and Murray won their second encounter in the fourth round of the US Open in 2012 in straight sets en route to winning his first Grand Slam singles title. The Canadian would win their next two meetings by winning in the semifinals of Tokyo in 2012 and in three sets in the fourth round of the BNP Paribas Open in Indian Wells in 2014.
Since then it has been one-way traffic by Murray winning their next seven encounters and Raonic managing just three sets in the process.
The Brit won their solitary meeting in 2015 in the quarterfinals of the Mutua Madrid Open, and followed this with a five set victory in the semifianls of the Australian Open this year, unfortunatley, the Canadian was visibly injured and couldn't compete at a high enough level to beat Murray.
Murray thrashed Raonic 6-2, 6-0 in their quarterfinal clash in the Monte Carlo Rolex Masters, a three set victory in the final of Queen's and they met a few weeks later in the final of Wimbledon which was Raonic's first Grand Slam singles final, which Murray won in straight sets but it was a closely contested match.
Murray won their most recent encounter in the semifinals of the Western and Southern Open in Cincinnati in August, and the duo were meant to meet in the semifinals in Paris earlier this month but Raonic withdrew from an injury which left a huge question mark over his participation in London.
Who reaches the final?
Both players have played some good tennis in London this week and both players have respective targets which will make this contest even more exciting.
Raonic will need to put in a good performance like he did against Djokovic, furthermore, it is vital that he takes opportunities that are given to him as it could come back to haunt him.
Murray is a good returner and has had success against big servers over the year, on the other hand, the world number one will need to hang onto his serve as if he is broken by Raonic, he will need to try break back which could be difficult, depending on how well the Canadian is serving.
The Brit is under immense pressure but he has dealt with it brilliantly so far, especially against Nishikori, he showed his character and shown why he is the current world number one.
Raonic is not expected to win this match, but he will play his game with big serves and forehands and he believes that he can win this match, however, he will need to improve on his backhand down the line which he struggles to generate a good amount of power to do damage.
Murray has the tools to force Raonic to come forward into this net, and the Brit has the ability to lob his tall opponents.
This will be the first of the two semifinals taking place on Saturday, and the winner of this match will face Novak Djokovic or Kei Nishikori in Sunday's showpiece final.
Plenty is at stake for both players, and this encounter in London shall be interesting for the fans to watch.
Prediction: Murray in straight sets.