Playing only his second final, Fritz made a solid start to break Querrey to love in his first return game.
Fritz went on to dominate the majority of the baseline rallies, while Querrey was undone by unforced errors in key moments of the match.
The 21-year-old Fritz clinched another early break of serve in the second set before closing out the victory in just over an hour with an ace.
Fritz, son of former top-10 player Kathy May, will look to carry his success over to Wimbledon, where he begins his campaign against Czech Tomas Berdych on Tuesday.
Querrey, who was playing his first final since the New York Open in 2018, will meet world number four Dominic Thiem in his opening match.
(Reporting by Hardik Vyas in Bengaluru; Editing by Toby Davis)