"It is the biggest title I have ever won", said Zverev.
The 21-year-old has always been thought of as a future world number one and he overcame a hostile reception following his win over Federer on Saturday to outmuscle Djokovic on Sunday at the O2 Arena for his 10th ATP Tour title.
As the head of German men's tennis I've been mentoring Sascha for the last two-and-a-half years so I have practised and travelled with him many times and know him very well. I'm not sure, maybe someone can tell me whether the player can do that.
But the South African could only land 48 percent of first serves in the first set and Djokovic was made sure Anderson pay for it, breaking in the first game and repeating the feat before serving out for the set. "I want to mention how good a person you are".
"I was very emotional afterwards".
'Even though we had a bit of a moment yesterday I still appreciate each and everyone coming out here and supporting me, ' he told the crowd. "Give me a smile, don't be too serious, please".
When these two met earlier in the week Zverev had a break point for 5-4 in the opening set but could not convert it.
In becoming the youngest ATP Finals champion since Djokovic, also 21, in 2008, Zverev sent out a clear message that he is ready to spend a considerable amount of time at tennis' top table and start accumulating the game's biggest prizes. Serve dominated the first set of a high-class match but the Swiss, a six-time champion at the Finals, eventually faltered in the 12th game.
'I'm here now. So I'm a little bit disappointed there because I believe I was close. Roger was on the point and was putting him on the back foot but you could see on the replay that it did actually happen. For him, it was the first defeat at the tournament in London.
Breezing through his own service games - he is yet to be broken this week - Djokovic was able to exert maximum pressure on Anderson's delivery and his opponent buckled to drop serve again as Djokovic pocketed a one-sided opener.
I talk to him about the old days, when I won Grand Slams, ATP Finals and was number one in the world, what I did in those certain situations.
"There's a lot of similarities in terms of trajectory.in our careers", said Djokovic, who ended a two-year Grand Slam title drought by winning Wimbledon this year, before going on to claim his 14th major trophy at the U.S. Open. I had to take a few minutes for myself. "And he's returning well, which definitely makes life hard, but that's why he's one of the best players of all time". Mischa, nearly 10 years older than his brother, reached the quarter-finals of last year's Australian Open, defeating then world number one Andy Murray along the way.