Medvedev wins!
Daniil Medvedev wins the match 6-3 6-3!
A final hold caps a brilliant effort from the fourth seed as he took command of this match from 3-2 down, ripping off seven games in a row and dictating in all areas. A well-deserved semifinal berth for Medvedev.
Djokovic didn't play his best, but he was beaten by the better man on the day. He'll face Alexander Zverev on Friday for a semifinal spot and based on today's performance, he'll need to be a lot better to take out the German.
This is John Lupo saying thanks for joining me and stay tuned for more coverage of the ATP Finals and join me again tomorrow as Dominic Thiem takes on Andrey Rublev.
So long for now.
Djokovic holds
Djokovic 3-6 3-5 *Medvedev
Novak will ask the question of his foe after another blazing hold.
Medvedev responds
*Djokovic 3-6 2-5 Medvedev
And an unreturned serve and two aces put the Russian a game from a much-deserved win.
Djokovic holds in a flash
Djokovic 3-6 2-4 *Medvedev
An easy hold to 15 for the world number one.
Medvedev comes through test
*Djokovic 3-6 1-4 Medvedev
At 30-30, the Russian blasted a backhand winner and forced Djokovic forehand miss as he closes in on victory.
Djokovic stops the streak
Djokovic 3-6 1-3 *Medvedev
Finally, Novak wins a game, although not without some work. He fell behind 15-30 with more erratic play, but rallied behind (of all things) his overhead on consecutive points.
Six games on the trot for Medvedev
*Djokovic 3-6 0-3 Medvedev
From deuce, Daniil throws in a pair of aces. Djokovic knelt down during that game, perhaps a sign of both physical and mental exhaustion.
Medvedev breaks!
Djokovic 3-6 0-2 *Medvedev
More brilliant stuff from the Russian as he continues to command the baseline and force Djokovic into more mistakes.
Medvedev holding with ease
*Djokovic 3-6 0-1 Medvedev
Superior serving from the Russian, who holds to love in the blink of an eye.
Medvedev wins the first set!
Daniil Medvedev wins the first set 6-3!
A horror game for the Serb, with three double faults and a forehand error. It must be said that Medvedev is forcing him into many of these mistakes.
Russian a game away
*Djokovic 3-5 Medvedev
A quick hold for Medvedev, who's on a roll now.
Medvedev breaks!
Djokovic 3-4 *Medvedev
What a game! 11 minutes long and the fourth seed is out in front after some aggressive play, forcing Novak into some mistakes, including on break point.
Medvedev serving well
*Djokovic 3-3 Medvedev
And the Russian holds to 15.
Djokovic back in front
Djokovic 3-2 *Medvedev
A much easier service game this time for the world number one.
Medvedev wins long service game
*Djokovic 2-2 Medvedev
The fourth seed wins a six-minute game, sealing it with a forehand to level the set once again.
Djokovic escapes trouble
Djokovic 2-1 *Medvedev
Novak gets out of 15-40 after winning a 30-shot rally and holds after consecutive Medvedev forehand errors.
Medvedev answers
*Djokovic 1-1 Medvedev
And the Russian answers with a hold to 15.
Djokovic holds
Djokovic 1-0 *Medvedev
A hold to 30 for the world number one as he slams an ace down the middle on game point.
How to watch
The match will start at 3pm Eastern time, 8pm London time and can be seen on the Tennis Channel.
Zverev, Schwartzman battle in first match of the day
Alexander Zverev and Diego Schwartzman will play the first match today with both players seeking their first victory in London.
Head-to-head
This is the seventh career meeting between Djokovic and Medvedev with the Serb holding a 4-2 edge, their most recent meeting at the ATP Cup earlier this year, Djokovic coming out on top 6-1, 5-7, 6-4.
Medvedev on the board
After going winless in his ATP Finals debut last year, the Russian scored his first win at the year-end showpiece with a 6-3, 6-4 victory over 2018 champion Alexander Zverev.
Djokovic off to a flyer
The world number one looked every bit that in his opening match, a convincing 6-3, 6-2 victory over Diego Schwartzman.
Welcome!
Hello and welcome to this crucial round robin match between top seed Novak Djokovic and fourth seed Daniil Medvedev in Group London 2020.
My name is John Lupo and I will be your host for this key matchup.