The Pole did not drop a set on his way to the final and produced yet another impressive outing to down Carreno Busta 7-6 (7-2) 6-3 in just 82 minutes.
Carreno Busta did, however, take an early lead and have Hurkacz reeling from a break down in the first set but the 24-year-old, who defeated former world number one Andy Murray this week, responded efficiently.
Having come from 3-1 down to 4-4, Hurkacz did not look back as his sharp first serve caused Carreno Busta all sorts of problems, most notably to secure the first-set tiebreaker with ease.
The pair continued to exchange breaks at the beginning of the second set but Hurkacz played well from the baseline and held serve to clinch his first trophy outside of the United States.
His victory means he holds a 4-0 record in ATP Tour finals and also saw him inflict revenge on Carreno Busta, who won the previous head-to-head clash in Cincinnati last month.
Hurkacz will be looking for doubles glory on Sunday as well, as he teams with international compatriot Jan Zielinski.