00:30 CET - Our pick of the action today in Turin was a brilliant rally between Novak Djokovic (36) and Hubert Hurkacz (26) in which the Pole out-muscled the world number one.
Despite coming into the tournament as a substitute, Hurkacz was no pushover, that's for sure!
23:45 CET - Jannik Sinner (22) has beaten Holger Rune (20) 6-2, 5-7, 6-4 to make it three wins from three in the ATP Finals group stage.
The result means that Novak Djokovic (36) goes through into the semi-finals along with Sinner from Group A.
There is still one semi-finalist to be decided in Group B tomorrow with the final four to play on Saturday.
19:20 CET - Next up in Turin, Italy's Jannik Sinner (22) takes on Denmark's Holger Rune (20).
As mentioned below, Novak Djokovic (36) needs Sinner to win, while a Rune victory would see the Dane go through to the semis with the already-qualified Italian.
Follow the action live from 21:00 CET.
16:57 CET - Novak Djokovic (36) has won his final group stage clash of the week, beating Hubert Hurkacz (26) - who stepped in to replace the injured Stefanos Tsitisipas (25) - 7-6, 4-6, 6-1.
It's not all good news for the Serb though, as due to the fact that he lost a set and the permutations below, he'll only advance to the semi-finals if Jannik Sinner (22) beats Holger Rune (20) tonight.
The Italian went through the moment that Hurkacz won the second set this evening, and the Dane rather than Djokovic will join him in the last four if he claims victory.
13:20 CET - The way the ATF Finals groups are poised, there is a very real possibility that two or even three players end up level on points in the group standings.
What happens then? Well, if the players can be separated by wins and two players are level on points, it reverts to head-to-head record.
If three players are level on points after the three rounds - which could well happen in both groups - the players are separated by the percentage of sets won.
That’s why Daniil Medvedev (27) has secured his spot in the semi-finals. Even though he, Carlos Alcaraz (20) and Alexander Zverev (26) could all end up level on points, his set percentage cannot end up lower than Zverev’s.
See the full standing here and read more about the tournament rules here.
11:35 CET - In case you missed the tennis yesterday in Turin, you catch up on the highlights below!
11:25 CET - The first match of the ATP Finals today sees top seed Novak Djokovic (36) take on Hubert Hurkacz (26), who replaced the injured Stefanos Tsitsipas (25) in Turin.
Djokovic was stunned by Jannik Sinner (22) in round two and so needs to win to secure a spot in the semi-finals.
Follow the action live here from 14:30 CET.
07:30 CET - We have some more fantastic action for you from the ATP Finals today, and by the end of the day, we will know the first two players to have booked their spots in the semi-finals.
At 14:30 CET, Novak Djokovic (36) takes on Hubert Hurkacz (26), who is replacing the injured Stefanos Tsitsipas (25).
At 21:00 CET, Jannik Sinner (22) faces Holger Rune (20).
