The Englishman beat former World Champion Rob Cross 16-8 and presented himself in top form just over a month before the World Championships.
By winning the Eric Bristow Trophy, the 28-year-old celebrated the second major title of his career in Wolverhampton, England.
Humphries had beaten James Wade 16-10 in the semi-finals.
His compatriot Cross booked his place in the final with a 16-13 win in an all-English duel against Stephen Bunting.
Humphries inflicted "Voltage" Cross's eighth defeat in a twelfth major final. "Cool Hand Luke" collected £150,000 in prize money.
The prestigious World Darts Championship will take place from December 15th to January 3rd, 2024 at Alexandra Palace in London.