The American carded a two-under 70 in the final round at Keene Trace Golf Club in Nicholasville in Kentucky, finishing at 26 under. Kelly Kraft finished second after also shooting a final-round 70, his bogey at the par-four 17th proving costly.
Hermans win was his second on the PGA Tour and first since the 2016 Houston Open.
Sepp Straka (66) finished outright third at 23 under, a shot ahead of Matt Jones (63) and Austin Cook (70).
