Saturday 19 November 2016 18:34, UK
All eyes will be on the battle between the world's top two players with world No 1 Andy Murray ready to stop Novak Djokovic from claiming a record-equalling sixth title when they head to London's O2 Arena.
Only the best eight singles players in the world qualify for the prestigious season-ending championships.
Reigning Australian and French Open champion Djokovic will be aiming to nail a sixth title in the capital while Murray has never won the season-ending tournament, but heads to the O2 full of confidence after winning the past four events.
More than one million people have attended the World Tour Finals at the magnificent O2, making it the world's biggest indoor tennis tournament, and the capital will continue its love affair with the event once again.
Here, we take a trip down memory lane and look back at the finals which have graced the 17,800 capacity O2 Arena...
Djokovic became a four-time defending champion when he successfully defended his title in his 15th final from 16 tournaments in a remarkable year for the Serb.
Roger Federer had ended Djokovic's streak of 38 consecutive indoor match wins, 23 overall this season and 15 straight at the World Tour Finals earlier that week, but the world No 1 cleverly adjusted his tactics to gain sweet revenge in the final.
"I am enjoying every moment on the court. I cherish every moment after dreaming of it as a kid. Thank you everyone for making this year so special," said Djokovic.
The 33-year-old Swiss announced he was "not match-fit" before the final after picking up a back injury, meaning Djokovic collected the trophy once again.
Federer apologised in person to the crowd, saying: "I'm sorry I'm not fit to play. I hope you understand. I wanted to come out personally and explain. I did everything I could. I took pain-killers, had rest until the very end, but I just cannot compete at this level with Novak. At my age it would've been a risk."
Tournament organisers arranged two exhibition matches to take the place of the final. Djokovic defeated Murray 8-5 in a pro set in the first match and the British No 1 then paired up with John McEnroe to beat Tim Henman and Pat Cash 8-6 in a doubles contest.
Djokovic completed a successful defence of his title with sweet revenge over his nemesis Nadal. His most recent defeat came against Nadal in the US Open final but there was little prospect of a repeat during a one-sided contest on the blue hardcourt in the capital.
The Serb was back in truly ominous form as he clinched his third win at the season-ending event to go with his triumph a year earlier and 2008 success in Shanghai. Victory was also his 22nd in a row and gave him a fourth straight tournament success to end the season having also won in Beijing, Shanghai and Paris over a remarkable six-week period.
"I am very proud of the way that I managed to recover and perform better and better as the tournament went on," he said.
Federer was back in the final and attempting to become the first player since Ivan Lendl to win three season-ending championship titles in a row. On his 11th appearance at the event Federer suffered a surprise defeat to Juan Martin del Potro in the group stage, but still made it through to another final with victory over Andy Murray.
Top-seed Djokovic was showing imperious form sailing through to the showpiece without as much as breaking a sweat. The Australian Open champion, who triumphed in Shanghai four years earlier in the event, showed great resilience to fight back and capture his sixth title of the season.
"It's very satisfying for my team and myself to conclude this fantastic season with a World Tour Finals win," said Djokovic. "I never got to the finals of this tournament in London. I wanted really to fight and I really wanted to get as far as I can in this tournament. Winning all the matches I played makes it even more special."
Federer became the most successful player at the season-ending championship, marking the 100th final of his career with his 70th title over the big-hitting Frenchman. At the age of 30 Federer showed that his hunger for success has not diminished as he successfully defended his crown, winning an unprecedented sixth title.
The master of court manipulation upped his tempo in the deciding set to run away with the match by the banks of the Thames and join Lendl on an unmatched 39 match wins at the tournament.
"I know it's one of my greatest accomplishments," said Federer who ended the season without a grand slam title for the first time since 2002. "This definitely is an amazing finish again to the season. I've never finished so strong. I couldn't be more happy, I couldn't be more exhausted."
This match was billed as the Ali versus Frazier of the tennis arena. Federer opened his year by winning his 16th Grand Slam title at the Australian Open and was ready for a rumble with the world No 1 from Spain, who was the bookies' favourite having collected his fifth French Open title, his second Wimbledon crown and completed his set of career slams at the US Open.
It was the first time for 24 years that the top two players on the Tour had contested the title match and the excitement in Greenwich was palpable with footballing legend Diego Maradona, Ronnie Wood of the Rolling Stones and American actor Kevin Spacey in attendance.
Federer came into the match having lost six of his past seven matches to the Spaniard but Nadal was plainly fatigued after his three-hour semi-final epic against Murray. Meanwhile, Federer was in imperious form and in the duo's first meeting in London since their legendary Wimbledon final in 2008, the mighty Swiss prevailed.
Few people backed Davydenko to take the title in the very first year the ATP Tour Finals were held at London's O2 Arena. But just 12 months after the Russian suffered defeat to Djokovic in the Masters Cup final in Shanghai, he was back at the main event and playing the best tennis of his life.
The 28-year-old from Volgograd had reached four major semi-finals, two on the clay of Roland Garros and two at the US Open.
He lost a tight group stage match to defending champion Djokovic, but then embarked on a winning streak, achieving his own personal 'Grand Slam' in beating Australian Open champion Nadal and Robin Soderling in the group stage, seeing off the winner of that year's French Open and Wimbledon titles Federer (for the first time in 13 attempts) in the semi-finals and then overcoming the giant 6ft 6in US Open champion Del Potro to win the most lucrative title of his career.
It was Davydenko's fifth title of the year and 19th of his career and even drew unique praise from his opponent in the final. "He's very fast," Del Potro said. "He plays like PlayStation. You know, he runs everywhere. It was very difficult to make winners."
Check our game-by-game coverage from all Group matches at the ATP World Tour Finals in London - including Andy Murray - on skysports.com/tennis, our app for mobile devices and iPad and our Twitter account @skysportstennis.
