24-year-old Zverev defeated world no.1 Novak Djokovic in the semi-finals on Saturday, then world no.2 Medvedev on Sunday to claim the crown with some world-class tennis.
The German ace is riding a wave of confidence following his sensational Olympic gold medal performance at the Tokyo 2020 Games in summer 2021, claiming his first Tour Finals victory since 2018 here in Italy.
"Look, I won the World Tour Finals, in the final against somebody I've lost five times in a row," Zverev said post-match, "so I had to play one of my best matches and I'm happy about that and happy to be going on holidays with this win."
When he received the trophy he thanked Medvedev personally after talking about the incredible tennis he's played this year saying "I mean you've beaten me five times in a row so thanks for letting me win one."
"It is special and I'm super thrilled, I'm super happy right now," he added.
Zverev asserted himself early in Turin breaking Medvedev's serve to make it 2-1 in the first set, hitting nine winners to the Russian's one in the first set which he closed out 6-4.
Many saw Medvedev, still buzzing after that US Open victory over Djokovic, as favourite - particularly as Zverev and Djokovic had gone the distance the day before, a three-setter with a tiebreak in the first set.
“Every time we play it takes hours,” Zverev said after Saturday's encounter, so surely he was a little tired?
Not a bit.
Full of energy and running, striking the ball true and finding the lines with confident backhand strokes and forehand crosses, Zverev looked like he'd had the day off relaxing in the nearby Italian Alps rather than going slugging it out with Djokovic.
Medvedev tried to change it up but nothing worked, drop shots fell short, passing shots went wide, and Zverev was everywhere.
The German had the luck too with net cords dropping on the US Open champion's side.
The second set started even better than the first for Zverev, breaking Medvedev's serve in the very first game and quickly going into a 3-1 lead playing exhibition tennis.
It looked like he would run away with it, but Medvedev dug deep to stay in touch.
But the break back never came, and Zverev finished it in style with an ace on match point.
Asked how he's feeling after a year in which he's won Olympic gold, two Masters 1000 titles and this ATP Finals triumph, Zverev said, "There's no better way to end the season than winning here so I'm obviously very happy and I'm also now very much looking forward to next year. I finished a match, I know, but we'll see what happens."
Victory was all the more impressive for Zverev considering that they were playing on Medvedev's favourite surface with the Russian winning 11 of his 12 tour-level titles on hard courts, including the US Open.
Next for Zverev is the quest for that elusive Slam title with the Australian Open in Melbourne in the second half of January his next opportunity.
Earlier, French pair Pierre-Hugues Herbert and Nicolas Mahut beat Rajeev Ram and Joe Salisbury 6-4, 7-6 (0) to regain the title they won for the first time in 2019.