Querrey, the No. 8 seed, won his third career ATP singles title with a 6-7 (3-7), 7-6 (7-5), 6-3 win over Isner.
The sixth-seeded Isner fell just short in his bid to join Marin Cilic as two-time 2010 tour winners.
Querrey pocketed $261,500 in prize money.
Copyright 2010 United Press International, Inc. (UPI).