The third-seeded Medvedev picked up his third title in six consecutive finals played since the tour returned to hard courts after Wimbledon in July. He also won the Masters 1000-level tournament in Cincinnati and the St. Petersburg trophy in that stretch.
Last month, Medvedev also made it to his first Grand Slam final at the US Open, where he challenged Rafael Nadal through five sets before the Spaniard secured his career 19th Grand Slam trophy.
"It's something outrageous what I've done in the last few months," Medvedev said on the court after his win. "I wouldn't have believed it."
In the news conference, Medvedev tried to explain what has changed to improve his results.
"Something clicked in my game in USA," he said. "I don't know why. I think it's just the hard work that I have been doing.
"But I started to understand even more about my game, even more I would say about my serve, about my volley, about everything, like kind of what do I have to do when?"
The 23-year-old Medvedev is currently 29-3 in matches played in the past six tournaments.
Medvedev leads the 2019 ATP Tour season in four categories. He's won the most matches at 59, won the most hard court matches at 46, won the most matches at Masters 1000 tournaments at 22, and reached the most finals at nine with four titles captured.
The fifth-seeded Zverev had won all four of his previous encounters against Medvedev, but all of those matches were played prior to this year, which has seen the Russian become nearly invincible of late.
"As I said yesterday you're probably the best player in the world right now and it's unbelievable," Zverev said to Medvedev during the on-court ceremony. "All the best to you."
Zverev presented Medvedev with two gifts -- back-to-back double faults at 30-30 in the 10th game -- to enable the Russian to secure the first set 6-4.
Earlier in the first set, Medvedev led 3-0, but Zverev was able to recoup that first service break on a fifth break point on the Russian's serve in the fifth game.
Clearly the two double faults shook any confidence Zverev might have had in the match. He quickly fell behind 5-0 before the German won his lone game in the second set.
The Russian served out the 73-minute match with an ace to capture his first career victory over Zverev.
"Confidence was the biggest factor today," Zverev said. "He's way more confident than I am.
"To beat a player like him you have to have confidence and you have to be playing better for a longer period of time and not just for one week."