The match looked to be going Wattimena's way as the Dutchman raced into a 2-0 lead, but 'Cool Hand' held firm to secure his second ProTour title this year.
Humphries averaged 104.74 across the tournament and finished with an average just under 105 in the final, underlining a return to form ahead of next week’s Premier League play-offs in London.
“When it clicks for me, it clicks for me. When it does, I think people see I’m one of the best players in the world," Humphries said.
“It sets a standard for myself. I can do this a lot more. It’s just up to me to provide it a lot more than I do.
“I remember thinking throughout parts of the day that I felt like I just couldn’t miss, and that’s always a dangerous person when you feel like that.”
Humphries started his day with a 6-3 win over Rhys Griffin, averaging 112.18, before posting further ton-plus averages against Yorick Hofkens, Justin Hood and Christian Kist.
'Cool Hand' then beat Wessel Nijman 6-3 and Danny Noppert 7-2 to reach the final.
Wattimena’s route included wins over Stephen Bunting and Kevin Doets, averaging more than 111 in his semi-final victory over the latter.
Results
Last 16
Wessel Nijman 6-5 Andrew Gilding
Luke Humphries 6-2 Christian Kist
Rob Owen 6-2 Maik Kuivenhoven
Danny Noppert 6-3 Ryan Searle
Dirk van Duijvenbode 6-2 Ross Smith
Kevin Doets 6-2 Ross Smith
Stephen Bunting 6-5 Damon Heta
Jermaine Wattimena 6-2 Dimitri Van den Bergh
Quarter-finals
Luke Humphries 6-3 Wessel Nijman
Danny Noppert 6-5 Rob Owen
Kevin Doets 6-4 Dirk van Duijvenbode
Jermaine Wattimena 6-3 Stephen Bunting
Semi-finals
Luke Humphries 7-3 Danny Noppert
Jermaine Wattimena 7-2 Kevin Doets
Final
Luke Humphries 8-4 Jermaine Wattimena