Daniil Medvedev had just won the biggest title of his career, "the best victory" of his life at the ATP Finals, but did not celebrate.

And if he wins many more titles, even one of tennis' Grand Slams, he says he will do the same again.

"That is going to be my thing," the 24-year-old Russian said after Sunday's 4-6 7-6 (7-2) 6-4 win in London.

"In tennis I think I probably am the first one, definitely in football I have seen players who do not celebrate.

"I decided during the US Open when I had tough time with the crowd.

"I don't celebrate my victories. That is my thing and I like it."

That "tough time" he references at the 2019 US Open looks to have been a key moment in the making of Medvedev.

He was booed by the American public for bad behaviour on court in the early rounds but by the time he completed a run to the final he had won them over with a joke and a smile.

That day - his first appearance in a Slam final - he lost in five sets to Rafael Nadal.

Fourteen months later he beat the Spaniard en route to a stunning victory at the O2 Arena that made clear his credentials as a future star of the game.

He was unbeaten throughout, defeating world number one Novak Djokovic in the group stage, world number two Nadal in the semi-finals and world number three Thiem in the final. Never in its 50-year history had someone beaten the world's top three players at the season-ending championships.

"My level of game here, especially the last two matches, is just unbelievable," he said.

"To beat Dominic, the way he played today, is probably the best victory of my life.

"I know I can play good but I would not have believed this if you told me before the tournament."

Medvedev was engaging as he spoke freely to the media after his win. He is not necessarily your typical modern-day tennis player.

Thiem is a supreme athlete and thunderous hitter, Stefanos Tsitsipas, another young pretender, is energetic and graceful, while 23-year-old Alexander Zverev has a game built around a big first serve and forehand.

Medvedev is lanky, technically a little awkward in comparison to those others.

He has impressive power but that is blended with crafty angles and, against Thiem, a willingness to come into the net.

It is a style that has already sent him on hot streaks. Last year he reached six successive finals, culminating in the defeat by Nadal in New York, to bring him to the world's wider attention for the first time as a top-10 player.

This victory in London takes his winning run to 10 matches, having also claimed the Paris Masters title in the build-up to the season finale.

But it has not always been straightforward.

"Even before Paris I was feeling not confident in my game and my tennis," he said. "I proved myself wrong."

Now, attention turns to the future. Having won the biggest prize in tennis away from the Grand Slams, there will inevitably be those who think he is best-placed to dethrone Djokovic, Nadal and Roger Federer at the top of the game.

But Medvedev is the fifth first-time winner of the season-ending tournament in a row, following Andy Murray, Grigor Dimitrov, Zverev and Tsitsipas, and Murray is the only one of the other four to have won a Grand Slam. It was, in fact, Thiem who broke the 'Big Three's' stranglehold on the game by becoming the first new men's major champion since 2014 at this year's US Open.

Winning the ATP Finals does not guarantee Grand Slam success but this year did feel different with Nadal and Djokovic both beaten by younger men on the same day in the semi-finals.

"Hopefully, all of us young guys will continue pushing, will have some great rivalries," Medvedev said.

"Hopefully we can be there for a long time, maybe pushing the other generations back, because that's how we can be close to the top three. They probably went through two, three generations without dropping their level, which is not easy.

"But what is definitely good from us, from Dominic, from me, we managed both to beat Rafa and Novak, which is an amazing accomplishment."

Thiem was equally positive despite defeat.

"We proved we can play with the legends and also beat them and win the biggest tournaments," he said.

"There will still be a time when those guys retire in three, four or five years and we will be the favourites for all the big titles. For tennis, there are some exciting times ahead."

Djokovic, Nadal and Federer have proven people wrong time and again.

Their presence in an uncertain 2021 season will mean we cannot guarantee seeing Medvedev's 'non-celebration' on the biggest stage next year, but we might.