Medvedev came out of the blocks fast and Nishikori, aiming for his third title at this event, could not cope with the big-hitting Russian who broke his serve at the second time of asking.
After that it was a story of mistakes by world number 12 Nishikori — 11 unforced errors in the first set – and consistent serving by Medvedev who strolled to a 6-2 first set in just 25 minutes.
Nishikori corrected issues with his own serve in the second set but still could not have an impact on Medvedev’s service games, winning only one point on the Russian’s serve during the entirety of the second set.
Medvedev bided his time and broke a tired Nishikori, whose final shot was another wild miss, to wrap up the victory and secure a third ATP title of the season.
“I was playing amazing and I am so happy to come out on top,” said Medvedev, who will jump to no. 22 in the world rankings, after winning in just over an hour.
“To play seven matches and losing only one set, this makes me extremely happy.”
Medvedev has defeated Milos Raonic and Diego Schwartzmann en route to Sunday’s final and did not drop a single service game in his last three matches.
“The serve is the most important thing in tennis right now,” the 22-year-old added.
Nishikori has now lost eight ATP finals since his last victory, which came at the Memphis Open in February 2016.