The Russian received 6-3 6-4 after a bruising encounter, with each males wanting exhausted by the top of the match.
The first six video games alone took greater than 40 minutes to finish and had been crammed full with lung-busting rallies.
Despite the fatigue, Medvedev nonetheless had the presence of thoughts to efficiently execute an underarm serve while 4-3 forward within the second set. Zverev was in a position to return the cheeky serve however was unable to get better to win the purpose.
“I didn’t want to disrespect him (Zverev) but my wide serve was not working as well as I would like today and he was returning it good,” Medvedev mentioned after the match.
“I saw he was five meters behind the baseline and I had the ball close to my racket, so I was like ‘just go for it.’ It was just a move to win the point.
“I’m comfortable that it labored as a result of it is also good.”
It was Medvedev’s first win at the ATP Finals and his third consecutive victory over Zverev, who continued to struggle with his second serve, winning just four of the 19 second points from it.
In truth, the 2018 champion never really found his rhythm in the match after he hit four double faults in his first two service games.
Meanwhile, Medvedev will hope to continue his good form when he faces Novak Djokovic in the next round of matches.
Earlier in the day, the Serbian got off to the perfect start by beating Diego Schwartzman 6-3 6-1.
The 33-year-old Djokovic is bidding to draw level with Roger Federer with a record-equaling sixth ATP title and was dominant from the very start against his Argentine opponent.
“The second set I began swinging via the ball extra and with much less hesitation,” Djokovic said after the match. “I used to be more than happy with the way in which I performed.”
The season-ending match pits eight of one of the best male singles gamers and doubles groups collectively in a round-robin format. The 4 finest gamers then progress to the knockout levels.
It’s being performed on the O2 Arena in London for the final time earlier than it strikes to Turin in 2021.
However, there will not be an opportunity for followers to say farewell to the stage that is hosted the Finals since 2009, with matches being performed behind closed doorways because of the pandemic.