All that's left for me to do is point you in the direction of
Piers Newbery's match report.
I'll be back to guide you through both matches on day three, the second of which should be a corker. Goodnight.
So the first round of singles matches are now complete. In Group A, Federer leads the way from Murray while over in Group B, Robin Soderling heads Djokovic. Soderling got the day started with a shock win against world number two Rafael Nadal and he will play Davydenko in a top-of-the-table clash on Wednesday.
What a way to bring the curtain down on day two of the ATP World Tour Finals to at London's O2 Arena. Comfortably the most gripping match of the tournament to date and one that aptly whets the appetite ahead of day three, when Juan Martin del Potro and Fernando Verdasco will provide the warm-up act to Andy Murray's eagerly-anticipated meeting with Roger Federer.
And a special tribute from Djokovic to those of you who went the distance at the O2 Arena:
"I want to thank all the people who stayed this late. I'm excited to be here, it's a great venue and a pleasure to be playing in front of you guys."
Novak Djokovic on his victory:
"I didn't feel great on the court today - I'm definitely not the fittest guy on the tour right now. He was the better player in the first two sets. I was lucky to get through and win this. I was fighting for every service game and in the end I'm happy with the performance."
The players exchange shirts at the final whistle... I mean the end of the match. When did tennis turn into football?
Djokovic 3-6 6-4 7-5 Davydenko
Thank goodness for that. I had one foot out of the door when Djokovic puts a backhand into the tramlines to fall 0-15 behind. But Davydenko twice goes long before netting to give the world number three two match points. Davydenko saves the first with an outrageous winner but he goes long on the second and, finally, I can say game set and match Djokovic
*Djokovic 3-6 6-4 6-5 Davydenko
As anti-climaxes go that was up there with a Derren Brown live seance. Djokovic breaks Davydenko to love. The Russian has run out of steam. If Djokovic fails to serve out now, I'm going home.
Djokovic 3-6 6-4 5-5 Davydenko*
Djokovic is officially his own worst enemy. He comes out to serve for the match looking like a bag of nerves and is duly punished. A truly outstanding backhand winner down the line confirms his fate and boy will the Serb be kicking himself. Brilliant from Davydenko.
Mike via text on 81111
"Not best pleased with the scheduling. Must catch the train. Did they not except tight close matches between the world's top players?"
*Djokovic 3-6 6-4 5-4 Davydenko
A dodgy start from Davydenko, who is expertly lobbed by Djokovic. The Serb, contesting his 95th singles match of the season, fails to keep pace with his opponent thereafter, though, and Davydenko storms through for the second game running. Huge credit to the Russian, top stuff. Djokovic to serve for the match.
Anon via text on 81111
"Davydenko's head is reminiscent of a peanut and he must be nuts if he thinks he is going to win this one!"
Djokovic 3-6 6-4 5-3 Davydenko*
Not convincing from Djokovic but he makes it through when Davydenko goes wide with a fizzing forehand. The Russian now serving to stay in the match. Any of you still awake?
*Djokovic 3-6 6-4 4-3 Davydenko
Don't you be going anywhere just yet, people. Davydenko races back to within touching distance of Djokovic with a resounding service game. A 126mph ace helps him on his way. Djokovic looked to be cruising towards victory not so long ago but he's being made to work extremely hard for every single point now. Certainly the best match of the tournament so far.
Claire and Kim via text on 81111
"The O2 is not emptying in anticipation of Djokovic win... it's because we have to get home. We had to leave at 10 so as to get train back to Oxford."
Djokovic 3-6 6-4 4-2 Davydenko*
Can anyone tell me why Djokovic needs to take 19 bounces of the ball between each serve? It seems like the Serb is attempting to slow things down and disrupt his opponent's rhythm. It fails to prevent Davydenko bringing up a couple of deserved break points. Could the Russian be about to force his way back into this match? Numerous break points and game points come and go. The tension is unbearable. Davydenko eventually nets a running forehand and it's a monumental hold for Djokovic. Don't think I've ever seen so many fist-pumps in my life.
Anon via text on 81111
"The measure of a truly world class player is their ability to dig deep when things are not going well. Fed and Djoko seem to be doing that. Murray needs to show it too. Fed v Djoko final."
*Djokovic 3-6 6-4 3-2 Davydenko
An ace sees Davydenko over the line and, to be fair, that was a solid service game from the Russian right-hander. The O2 Arena is emptying in anticipation of a Djokovic victory but Davydenko still has something to give from what I can see. That said, he must make an impression on the Djokovic serve sooner rather than later or it's curtains.For those of you getting public transport home from the O2, the final tube leaves Greenwich a 0016 GMT.
pottiella on 606:
"Davydenko's in a sorry state now...he was always going to lose if it went to a third - ironic given Nole's renowned fitness issues."
Djokovic 3-6 6-4 3-1 Davydenko*
Davydenko was playing some wonderful tennis early on but since Djokovic has stepped his game up, the Russian has been found wanting a little. Whereas early he would put together a string of winners, now he is interchanging winners with unforced errors on an all too regular basis. "One paced" is how David Felgate
describes Davydenko on BBC Radio Five live sports extra
*Djokovic 3-6 6-4 2-1 Davydenko
It was so important for Davydenko to hold there and he did, just. Djokovic has his fair share of chances, taking some and wasting others. The quality of Davydenko's play has dropped somewhat but he's still in this y'know. Djokovic sends a backhand into the tramlines to hand over the game.
sisivale on 606:
"I am going to predict Davy to break back later on and win this in the breaker. There's not been a breaker yet the whole championship."
Anon via text on 81111
"Me and my friend have been here two days and have watched every game so far, but having Roddick sit just a couple of seats away has made our tournament!"
Djokovic 3-6 6-4 2-0 Davydenko*
When you're a break up in the deciding set and your serve begins to click, it's happy days. Djokovic storms through with a couple of tremendous kicked serves out wide which clip the line and scorch past a helpless Davydenko.
*Djokovic 3-6 6-4 1-0 Davydenko
Scratchy start from Djokovic but a touch of luck, when a blistering forehand streaks past Davydenko after clipping the net-cord, sets the Serb on his way. Davydenko looks a tad forlorn after firing a forehand long and a chest-pumping Djokovic celebrates a first break of serve in the deciding set
. This seems like a carbon copy of yesterday's Federer-Verdasco match.
Djokovic 3-6 6-4 Davydenko*
He may have just clawed his way back into the match but not all is well with Djokovic today. The 22-year-old nervously drops a coupe of points early on and even has to save a break-back point. Davydenko looks, by some distance, the more comfortable of the two players. But Djokovic eventually engineers a set point and takes it at the first time of asking. Fist pumps galore and we're heading for a deciding set.
*Djokovic 3-6 5-4 Davydenko
Now we have a match on our hands. Davydenko showed a few signs of creaking in game eight and they are confirmed in game nine. The Russian suddenly looks all at sea and, sensing a chance to pounce, Djokovic goes after his opponent like a lion to its prey. Davydenko nets twice and then shanks a forehand wide on break point. The 28-year-old challenges the call but Hawk-Eye shows it was well out. Djokovic is yelling and pumping his fist with delight. Serbia's finest to serve for the set
Djokovic 3-6 4-4 Davydenko*
After throwing away the first point, Djokovic looks more than a tad disconcerted. But he keeps his composure and, for the first time in a long time, Davydenko is guilty of several poor groundstrokes in a row. Djokovic thinks he's won the game with an ace and both players head for their chairs. But umpire Steve Ullrich calls a let, much to the Serb's displeasure. World number three Djoko swiftly sees out the game and lets out a deafening scream of "C'mon!" before taking a cursory passing glance at Ullrich.
bennie007 on 606:
"Wow, just got in - what have I missed? What? Everyone today who has was deemed 'the outsider' of the match is BEATING THEIR OPPONENT? Oh how the wheel of fortune turns..."
*Djokovic 3-6 3-4 Davydenko
Djokovic gets the better of Davydenko at the end of a mind-blowing rally to level at 15-15. But Davydenko hits back with a thunderous un-returnable serve and beautifully wrong-foots Djokovic to get his neck back out in front. Suffice to say, if the Russian breaks now he'll be serving for the match. Crikey.
Djokovic 3-6 3-3 Davydenko*
A hold to love. Just what the doctor ordered as far as Djokovic is concerned. "Nothing better than putting your opponent straight back into bat," says David Felgate of 5 live sports extra.
David Felgate on BBC Radio 5 live sports extra:
"Djokovic is throwing his toys out of the pram. And in that situation the last person you want to see on the other side of the net is Nikolay Davydenko. Djokovic is a Grand Slam winner, he should know how to deal with these situations. Perhaps this is why he hasn't won more Grand Slams."
*Djokovic 3-6 2-3 Davydenko
By far the most aggressive game we've seen Djokovic produce for some time and he is rewarded with two break points. But his concentration is broken by a red light on top of a camera in his line of vision and Davydenko powers his way to game point. An exasperated Djokovic again looks up to his support team but I'm afraid, young man, they can't do anything to help you. Almost out of frustration, the Serb opens up his body and lashes a petulant forehand into the tramlines.
Djokovic 3-6 2-2 Davydenko*
Nice hold, Novak, nice hold. Looks to be sailing through the game before Nikolay 'the wall' Davydenko popped up with a couple of laser-guided winners. But the Russian goes well long to end the game. Novak looks pumped.
*Djokovic 3-6 1-2 Davydenko
I officially know nothing. To be fair, Djokovic pushes hard for the break of serve early on and works his way to 30-30. A couple of unforced errors from Davydenko suggest there could be something in this game for the Serb. But he plays a couple of wayward groundstrokes, smashes his racquet into the court, gets booed by the crowed and Davydenko comes through. The boos turn to cheers when world number six Andy Roddick, missing this tournament through injury, appears on the big screen TV from his seat in the crowd.
Djokovic 3-6 1-1 Davydenko*
No better a way to bounce back from a break against than to hold with consummate ease. Djokovic exuded authority during that game and his body language would suggest he's ready to up the ante.
*Djokovic 3-6 0-1 Davydenko
Comfortable hold for world number seven Davydenko. He battles his way to 40-15 and, after letting Djokovic back in, sees out the game with the benefit of a successful Hawk-Eye challenge.
Djokovic 3-6 Davydenko*
The O2 Arena is stunned. A double fault gets Djokovic off to a poor start and Davydenko is now in control. He comes to the net and smashes his way to two set points before looping a wonderful return towards the baseline. Praying it will drift long, Djokovic stands rooted. But it drops in and the first set goes to Davydenko
. The world's top three have now all conceded the first set of their opening matches. If Djokovic loses the match he will play Rafa Nadal on Wednesday, with the loser all but certain of going home.
*Djokovic 3-5 Davydenko
Brilliant service game from Davydenko, summed up by a sensational forehand winner down the line. The Russian's footwork, movement, shot selection and timing take the breath away at times. Djokovic now serving to stay in the set. Each of the world's top three have now been in this position. What's going on?
Djokovic 3-4 Davydenko*
Normal service resumed as Djokovic holds to love. I can't help but reiterate how high the technical level is out there - these fans are being given a real treat. Davydenko surrenders the game by netting a backhand and the pressure is now back on the 28-year-old Russian, who will serve for a 5-3 lead.
*Djokovic 2-4 Davydenko
Having just secured a break, it was crucially important for Davydenko to hold serve the following game. A stunning forehand passing shot down the line helps Djokovic bring up a break-back point but Davydenko rescues the situation and seals the game when his 22-year-old opponent goes long.
Djokovic 2-3 Davydenko*
Out of nowhere, Davydenko races 0-40 up and finds himself with three break points. He hadn't seriously challenged the Djokovic serve hitherto but his calm, consistent and accurate groundstrokes are finally rewarded. The first break of the match
arrives when Djokovic nets a backhand. The Serb glares at his support team in the stands. This first set is getting very tasty.
*Djokovic 2-2 Davydenko
Djokovic begins to apply some real pressure on the Davydenko serve and, despite falling 40-15 behind, quickly brings up deuce. Djokovic is sliding around the surface as if it was clay, retrieving balls he has no right to be getting near. Hats off to Davydenko's doggedness in defence - he repels one booming backhand after the next before Djokovic goes wide and hands over the game.
Djokovic 2-1 Davydenko*
As expected, Djokovic is making most of the running out there but Davydenko will be no pushover. The Russian takes world number three Djokovic to 30-30 but nets a backhand volley and then fires into the tramlines. Djokovic arrived in London in red hot form - and I'm not just referring to his choice of shirt tonight - as
Piers Newbery explains.
David Felgate on BBC Radio 5 live sports extra:
"Best opening two games we've seen all tournament - great hitting, great timing."
*Djokovic 1-1 Davydenko
Chair umpire Steve Ullrich form Tampa, Florida, pleads with the spectators to refrain from using flash photography but it doesn't seem to be effecting either player. And you can't blame the fans for wanting a permanent memento of these two. I've covered the opening four matches of the tournament and this is easily the most aesthetically pleasing start we've been treated to. Davydenko gets on the scoreboard as Djokovic nets a volley.
Bourne on 606:
"Djoko to fade away in the second set, Davy will be all over him once he gets into his rhythm."
Djokovic 1-0 Davydenko*
A solid start from both men. A couple of winners each, an unforced error here or there. Davydenko goes long with a whipped forehand to hand Djokovic the opening game.* Denotes next to serve.
Oh, I forgot to mention that Tim Henman's former coach David Felgate is in the sports extra commentary box so listen in. Davydenko, by the way, is appearing in his fifth successive end-of-season tournament. That's some achievement. He beat Djokovic in the Shanghai final recently and the Serb admits, "he's a difficult opponent - he moves well and is very aggressive so I'll have to take my chances."
Djokovic tells BBC Radio 5 live sports extra he has been working with Todd Martin at improving his aggression and ability to take control of a match. You can here ball-by-ball commentary and analysis of this match on BBC Radio 5 live sports extra
Huge cheers from the capacity crowd as Davydenko and Djokovic receive their boxing-style introductions. They're knocking up on court - Davydenko in black top and white shorts socks and shoes, Djokovic in an eye-catching red shirt, black shorts and red shoes.
Please do get involved in the chat. You can do so by text to 81111,
There have also been shocks in the doubles today, with Max Mirnyi and Andy Ram beating second seeds Mike and Bob Bryan and Lukas Kubot and Oliver Marach overcoming Lukas Dlouhy and Leander Paes. Those results came after top seeds Daniel Nestor and Nenad Zimonjic lost their opener on Sunday. Will Davydenko continue the trend?
In the other Group A match earlier today, Robin Soderling stunned world number two Rafael Nadal. Check out Piers Newbery's report:
BBC Radio 5 live sports extra's David Law on Twitter:
"Some brilliant articles giving me all the background I need on Djokovic. I can find NOTHING on Davydenko. Poor bloke. Much maligned is Davydenko, but it's so harsh. He's finished 5th, 3rd, 4th and 5th in the year-end rankings since 2005. Deserves respect."
The world number three gets his ATP Tour Finals campaign under way against the man he beat in last year's final, Nikolay Davydenko. In four previous meetings, the pair lay claim to two victories apiece. So on paper, at least, this has all the makings of a belter.
He's the tournament's defending champion. He's currently the game's in-form player. And in about 15 minutes he's going to be walking out in front of 17,500 fans at London's 02 Arena. Yes ladies and gentlemen, it's time for Novak Djokovic.