Postpublished at 14:09 Greenwich Mean Time 12 November 2017
Federer v Sock
The umpire Mohamed Lahyani is mic'd up as he gets the players together for the coin toss.
Roger Federer wins it and chooses to receive.
The warm-ups are under way.
Summary
Alexander Zverev (Ger) bt Marin Cilic (Cro) 6-4 3-6 6-4
Roger Federer (Swi) bt Jack Sock (US) 6-4 7-6 (7-4)
Postpublished at 14:09 Greenwich Mean Time 12 November 2017
Postpublished at 14:08 Greenwich Mean Time 12 November 2017
Federer v Sock
There is no tournament quite like the ATP Tour Finals.
The O2 Arena is plunged into darkness before the players head out onto the court.
It'll be no surprise to you that Roger Federer won the 'loudest cheer award' from the 17,000 fans as he and Jack Sock were introduced.
Image source, ReutersWho plays who?published at 14:05 Greenwich Mean Time 12 November 2017
Most of you will know how this works by now but I'll run you through it nonetheless.
The eight players who have collected the most points throughout 2017 have all qualified for the ATP Tour Finals this week.
There are a few notable absentees - namely Andy Murray, Novak Djokovic and Stan Wawrinka - but Roger Federer and Rafael Nadal, the winners of this year's four Grand Slams, are here as well as the rest of the world's best.
The players are split into two round robin groups with the top two finishers in each group qualifying for the semi-finals ahead of the final next Sunday.
Who can end 2017 in style?published at 14:03 Greenwich Mean Time 12 November 2017
Image source, Rex FeaturesHello there!
It's that time of year again. After a thrilling 11 months of tennis, the season's best eight male players all head to the O2 Arena in London for the ATP Tour Finals.
This time next week one man will finish the season with another trophy to their name but before then there is a whole lot of high-class tennis to get through.
Today is day one and first up is the second seed and 19-time Grand Slam champion Roger Federer against American Jack Sock.
Don't go anywhere...
Postpublished at 14:00 Greenwich Mean Time 12 November 2017
2017 has been quite a year. A year when two of the all-time greats defied age to dominate the Grand Slams.
Image source, Getty ImagesAll eyes are now on London for the season finale and both have the chance to finish the year in style.
But will one of the chasing back spoil the party?
Image source, Getty ImagesOver the next week we'll find out...