The Dutchman, who produced a sequence of near-perfect performances across the weekend, secured his maiden European Tour crown and the £35,000 winner's prize, with the result launching the 25-year-old into the world's top 20.
Nijman raced out of the blocks in the final, taking the opening three legs with finishes of 116, 64 and 86.
Price briefly halted the surge, but the Dutchman soon reasserted control, producing back-to-back combinations of 97 and 145 to storm into a commanding 6-1 lead.
Even when Price responded with a tidy 14-dart hold, Nijman remained unflustered.
An 11-dart leg moved him within touching distance of the title before he sealed the triumph in spectacular fashion, landing a brilliant 150 checkout on double 18 to complete an emphatic 8-3 victory.
Nijman averaged 100.8 in the final and converted an exceptional 73 per cent of his chances at double, underlining the clinical finishing that defined his entire campaign.
'I felt great all day'
"I think there are no words to describe how I'm feeling right now," Nijman said afterwards.
"I felt so great all day long. I think you saw when I played Gian, Josh and Niels, I played so well.
"I thought to myself: 'This could be the day you win a title', and I'm so happy I did.
"Since I stopped working, I'm feeling so confident. I'm practising more and more now; I've never put this many hours in on the board.
"I didn't need to prove anything to myself. I needed to prove to other people that I can play like this on the big stage.
"I'm doing it now in a European Tour event and I hope I can do it in the biggest major events, so I can show the world that I'm capable of winning any event there is.
"The main goal was to get into the top 16 and be a seeded player in major tournaments, and I think this is a big step towards that."
Big names dispatched
After surviving a stern opening test against Cristo Reyes on Friday, Nijman embarked on a blistering run that featured five consecutive ton-plus averages, dismantling a succession of high-calibre opponents.
His charge gathered serious momentum on Saturday with a clinical 6-2 victory over Mike De Decker, before Sunday's decisive session began with a stunning display against European Champion and World Championship finalist Gian van Veen.
Nijman averaged a staggering 112.87 in that contest, the highest stage average of his career, as he swept past his compatriot 6-1.
That performance set the tone for the remainder of the day. In the quarter-finals, he dispatched Premier League star Josh Rock 6-2 with a 106 average and barely missed out on a spectacular nine-dart finish.
The semi-finals proved equally one-sided. Nijman dominated Niels Zonneveld 7-1, averaging 110.41 while converting 64 per cent of his attempts at double.
