Andy Murray has beaten Novak Djokovic and won the ATP World Tour Finals in London to stay as the number one player in the world - something he will carry into 2017.
The 29-year-old Scot becomes the 26th man to reach the top of the men's standings since the system began in 1973.
He's got a long road ahead of him if he wants to hold the top spot as long as previous number ones - such as the longest standing Roger Federer with 302 total weeks at the top. However, he becomes the first player other than Djokovic, Federer or Rafael Nadal to hold the position since Andy Roddick in 2004.
So how has Murray reach this point? We take a look at the key events which brought him here.
1. US Open junior title (September 2004)
Victory over Sergiy Stakhovsky at the age of 17 cemented his position as Britain's brightest hope.
2. First ATP Tour final (September 2005)
Murray reached the final of the Thailand Open before losing to Roger Federer.
3. Maiden ATP Tour title (February 2006)
Victory over Andy Roddick and Lleyton Hewitt gave Murray the title in San Jose and a place in the top 50.
4. Top-10 debut (April 2007)
Murray breaks into the top 10 for the first time after reaching the semi-finals of the Masters events in Indian Wells and Miami. He lost in the semi-final to a rather young looking Novak Djokovic.
5. US Open breakthrough (September 2008)
Murray beat Rafael Nadal for the first time when they met in the semi-finals at Flushing Meadows. Federer was a class act in the final however, overpowering the 21-year-old Murray.
6. First Wimbledon final (July 2012)
Murray ended the 74-year wait for a British men's singles Wimbledon finalist but again was unable to make the next step, losing in four sets to - that man again - Federer.
Roger shouldn't have got quite so comfortable with the win though...
7. Olympic gold (August 2012)
Murray bounced back with a 6-2 6-1 6-4 victory against Federer at Wimbledon in the Olympic final before partnering Laura Robson to silver in the mixed doubles.
No hard feelings Roger.
8. A grand slam title, at last (September 2012)
Buoyed by Olympic success, Murray reached the final of the US Open. From two sets up against Novak Djokovic, he was pegged back, but the Scot found something extra and triumphed in five.
9. Wimbledon glory (July 2013)
Murray survived a nerve-shredding last game to clinch a 6-4 7-5 6-4 win against world number one Djokovic to finally end Fred Perry's 77-year reign as the last home men's singles champion.
10. Davis Cup heroics (November 2015)
Of all Murray's successes, guiding Britain to the Davis Cup title was the most unlikely. The Scot won 11 of Britain's 12 points, including three in doubles with brother Jamie.
11. Fifth Melbourne final (January 2016)
Murray's search for an elusive Australian Open title goes on after his fourth final loss to Djokovic.
12. French Open final (June 2016)
Having turned himself into one of the world's best clay-courters, Murray completed his set of slam finals by reaching the decider in Paris but the result was familiar - defeat by Djokovic.
13. Second Wimbledon title (July 2016)
Murray stamped his class on proceedings against first-time slam finalist Milos Raonic to triumph 6-4 7-6 (7/3) 7-6 (7/2) and claim his third grand slam title.
Move over Federer and Djokovic, this was Murray's turn to be getting cosy with that trophy.
14. Olympic gold again (August 2016)
As part of a career-best run of 22 straight victories, Murray became the first tennis player to retain an Olympic singles title with a gruelling victory over Juan Martin del Potro in Rio.
15. World number one (November 2016)
Murray reaches the final of the Paribas Masters in Paris after his semi-final opponent Milos Raonic withdraws due to injury. Murray went on to beat John Isner 6-3 6-7 (4/7) 6-4 in the final.
Finally, Murray's win at the ATP World Tour finals this weekend cemented his position at the top of world tennis.
Muzza. We salute you.