|Place: O2 Arena, London dates: 11 to 18. November|
|coverage: Track live channels on BBC TV, radio, BBC Sport and mobile app. Live text comment is available for selected matches.|
World number one Novak Djokovic became the first person to have achieved the ATP finals in the finals after Alexander Zverev's clinical victory and a good result during the second match of the group.
After a very physical and close first set, the 31-year-old Kreivi ran away to win the German 6-4 6-1.
Djokovic, who rides in the first ATP finals since 2015, reached the last four when Marin Cilic defeated John Isner later.
"I do not think it was a breathtaking tennis, but victory is a win," he said.
"I played well in the middle of the second stage and started to swing through the ball.
"I had not served so well, but he did a lot of violent mistakes that helped me overcome."
In fact, it was Zverev's double fault that gave Djokovic the first set and a total of 33 inevitable mistakes affecting the fall of 21-year-olds.
Djokovic plays Cilicia in the final round of matches on Friday, while Zverev takes on Isner.
Are you Mr Bendy, Novak?
It took before the ninth game for the first set of either of the players to modify the skill point, Zverev misses two games.
After leaving this pressure, Djokovic left it until the perfect time to break into the next game – taking a set when a German double defeat.
It was an unfortunate way for Zverev to stay behind, as he had influenced her serving until then, delivering seven aces and one game that fired three consecutive returns over 140 meters.
Some come to the Grand Slam Prize winner, Zverev showed something of his talent against beautiful passes, but he was an opponent of a player who could break his body for almost anything.
Djokovic met one of Zverev's bodies serving his country with an extraordinary appearance that looked more like protecting his face – but of course the return went – and later Zverev needed two to try to hit the ball when the first opponent had done it.
"It's the first -" Mr Bendy, "" the Serbian laughed in his interview. "I rely on flexibility, and I was happy to surround people who emphasized the importance of stretching and paid for."
Djokovic is a favorite to win the sixth round of the season's finals after a remarkable year in which he came back to the elbow in order to win Wimbledon and US Open and returned to the top of the ranking list for the first time in two years.
The top two of the two four-player groups will allow Saturday's finals and the winners of these matches in Sunday's final.
Where did Zvereville go wrong?
The turning point for the match was Djokovic's 4-4, while Zverev went 0-30 up. But backward and then backward the mistake wiped off the advantage and the German bouncing the paint out of the country frustration.
Djokovic found a point at Zverev, which he lost after returning to Serbia and gave him another chance with a double defeat, but the young man stayed at this break when the tried salmon drove a long time.
Eventually Djokovic liked his service with a beautiful drop and never looked back.
Three mistakes in a row in the next match gave Djokovic the first points of his match and when Zverev saved one of them from the break, he took the series away from the first set.
The second opening was close, Djokovic shot his shoes when he could not break into Zverev's first maintenance game that had taken him to the guy.
But then Djokovic turned to the bolt and the German took only three points out of five to five when the 14-time Grand Slam champion fled victory for an hour and 16 minutes.
"It's important to understand the situation – Zverev is currently playing the best player in the world when he plays some of the best of his tennis. It's great that he understands where he is," former British number one Tim Henman said on BBC TV.
"If he really wants to hit the Grand Slams – something that has not happened so far – he has to test himself on the level and it was in a nutshell. It's easy to be impatient because he has won so much [three Masters 1000 titles are among his nine ATP titles] but he is still only 21 and is on his way. More and better things are coming. "
Former player and BBC commentator Andrew Castle:
This was a friend [Djokovic] which was not anywhere. He had lost his soul in the past two years, winning the French Open Competition in 2016. He had won everything. But he has been ignored now. I think it's great to see him back at its best. It's a great game. Everyone follows this and thinks "it is of a high standard".
This tournament starts to light up. We've had a lot of regular matches, but it was not one of them. Djokovic did not seem to think about it, but if that is the case, I would like to see him playing "well".