Alexander Zverev outplayed defending champion Daniil Medvedev to beat him for the first time in two years and win his second ATP Finals title.

Zverev, the 2018 champion, did not face a break point in a serving masterclass.

"I had to play one of my best matches," Zverev said after his sixth title of a year that included Olympic gold.

"I'm super thrilled and super happy right now. There is no better way to end the season than to win here."

Zverev, who beat world number one Novak Djokovic on Saturday, becomes only the fourth player to beat the top two players in the world in the semi-finals and final of this prestigious tournament and the first since Andre Agassi in 1990.

Zverev ends losing run against Medvedev

The pair had already met this week in Turin, with 25-year-old US Open champion Medvedev beating Zverev in a lengthy three-setter.

Zverev, 24, had lost to him five times since a victory over him at the 2019 ATP Finals in London.

But the 25-year-old Russian could not extend that winning run when the trophy was at stake as the German took an early break in both sets in a clinical display.

Zverev's serving was almost flawless as he dropped just four points on serve in the first set and won 83% of his first-serve points. It was therefore only fitting that he sealed victory with an ace.

"You beat me five times in a row, thank you for letting me win once," Zverev said to Medvedev during the trophy presentation.

This was the first final since the tournament's relocation from London and it was the first time since 2005 that the two finalists were aged 25 or younger.

Zverev already looking ahead to 2022

The ATP Finals, which feature the leading eight male players of the year, are second to only the Grand Slams in terms of prestige and are often a good indicator of future major champions.

Medvedev captured his maiden major title in New York this year after victory in the ATP Finals last year, while 20-time Grand Slam champions Novak Djokovic and Roger Federer are multiple winners.

Zverev beat Djokovic in 2018 to win what was then the biggest title of his career and while he is still waiting for his first Grand Slam title, he reached the US Open final in 2020 and this year won gold at the Tokyo Olympics.

Only moments after his latest trophy was in his hands, the German was already thinking about the future - and the main thing missing from his CV.

"I've kind of succeeded on every single level, there is only one thing missing, so I hope I can do that next year," Zverev told a news conference after what was an ATP-best 59th match win of the season.

With Federer and fellow 20-time major winner Nadal absent from the event through injury, Zverev and Medvedev are among those players showing that tennis has a bright future when those greats eventually step aside.

The Russian says Zverev can follow him into making the next leap into Grand Slam champion.

"He is a great player who is capable of beating anybody so he definitely can win a Grand Slam, it's just obvious, but he's not the only one and that's where it gets tough," he said, pointing to Greece's French Open runner-up Stefanos Tsitsipas.

"Is he capable? Yes. Is he going to do it? We never know."