The Ukrainian top seed needed three hours to overcome Czech ninth seed Bouzkova 7-5 4-6 6-4 in the decider of the WTA International event.
It marked Svitolina's 14th Tour crown but first since late 2018, when she won the WTA Finals.
Bouzkova, playing her first WTA Tour final, battled hard before falling short against the world number seven.
Svitolina came from a break down to win the opening set before Bouzkova levelled the match by taking the second.
There were five breaks of serve in the final set, with Bouzkova recovering from 4-1 and 5-2 down to get back on serve before getting broken in the 10th game.