The 20-year-old rising star will move up to number 20 in the world rankings after becoming the youngest champion in New Haven since Caroline Wozniacki in 2010.
"This is a great feeling," said the delighted Sabalenka, who blasted 29 winners.
"I will just work more, just to try to keep going, keep showing my best tennis, and we will see."
US Open
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Winner of the first five games in the opening set, Sabalenka twice broke error-prone Suarez Navarro. She closed out the set in the seventh game with a forehand winner after trailing 30-0.
Suarez Navarro, once a top 10 player, was more competitive in the second set taking a 2-1 lead and breaking Sabalenka to go 4-4.
In the crucial ninth game Suarez Navarro seemingly held but Sabalenka challenged an ace at 40-15 and won the discussion.
The Belarusian then broke to go ahead 5-4 and reached double match point in the next game.
Suarez Navarro wasn't finished, though, pulling within one point of leveling the set at 5-5 before Sabalenka took the final three points.
The final was the third of her career. She lost to Maria Sharapova in Tianjin last year and was defeated by Wozniacki at Eastbourne earlier this year.
"I didn't have some (career) plan," said Sabalenka. "I was just, like, 'Keep going, keep fighting.' Now I am 20 years old and I have my first title, so... it's okay."
US Open
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