Despite losing their past seven encounters, Van Gerwen had vowed to “teach a lesson” to his opponent.
Humphries averaged more than 104 – 11 more than his opponent – in the opening five legs but still went to the first break 3-2 down.
He made his scoring power count with four consecutive legs to take control of the match and when Van Gerwen broke his throw, Humphries immediately hit back with a superb 141 checkout to take the 12th leg.
The Dutchman upped his game, closed on the averages and finishes of 106 and 110 saw him level the contest at 12-12.
Humphries fought back and took out 131 to go 16-13 ahead before Van Gerwen hit 160 and 108 checkouts to cut the deficit, but he missed four darts at the double when poised to level.
He had three more chances again to take the next leg but Humphries finished in style with double double tops to clinch victory.
“I made mistakes and I still feel I was the better player. Luke is a fantastic player and we know what he is capable of. I think I deserved a little bit more today,” said Van Gerwen.
Earlier, Beau Greaves beat Fallon Sherrock 6-3 to successfully defend her women’s title.