Kvitova faced only one break point and was never broken as she remained unbeaten in seven career matches against her compatriot.
The second seed collected her 17th WTA title and her third in New Haven after victories in 2012 and 2014.
After a disappointing middle of the season during which she was slowed by a bout of mononucleosis, Kvitova will head to next week’s U.S. Open with renewed confidence, though she will need some rest before her first round match on Tuesday.
“I feel terrible, but doesn’t matter,” Kvitova told reporters. “I will have a day off. It was very tiring.”
Kvitova and fourth seed Safarova, left-handers born less than 150 km apart, wore identical outfits — red skirt, white top and red headband. They even had matching wristbands.
There was also little to separate them in the first set as both held serve easily before Safarova prevailed in the tiebreak.
However, Safarova, who did not face a break point in the first set, could not maintain her hot start and it was all Kvitova from then on as the world number five triumphed in a match that lasted two hours 18 minutes.
“She’s a big hitter,” Safarova said of Kvitova. “She’s putting a lot of pressure on you, serving really big. She was just going for it today, striking it well.”
Kvitova, the fifth seed at the U.S. Open, faces German Laura Siegemundin the first round in New York, a city she readily acknowledges she does not really like.
Sixth seed and losing French Open finalist Safarova will be up against Ukrainian Lesia Tsurenko in a rematch of their New Haven semi-final.
(Reporting by Andrew Both; Editing by John O’Brien)