The Welsh star becomes only the second player to reach double figures on the European Tour, averaging 99.87 across the tournament.
Price opened with a 6-4 win over Dave Chisnall before averaging 105.96 in a victory of the same scoreline against Chris Dobey.
He then edged past Martin Schindler in a deciding leg and beat Wessel Nijman 7-4 to reach the final.
Price took a 3-0 lead against Smith, but the Englishman responded with four consecutive legs to move ahead.
Price regained control with a 130 checkout in a 12-darter and moved 6-5 in front before closing out the match in 14 darts.
“I’ve been in the PDC for 12 years now, so less than one a year on average isn’t very good,” joked Price.
“I was 3-0 up, then 4-3 down, and Ross started smashing the trebles in for fun. I was hanging on and hoping I got more opportunities, and I did.
“Thankfully, I won this one, and hopefully it will give me a bit of confidence going forward. I was just struggling to get over the winning line. I lost in the last European Tour final that I played in.
“I never used to have this support, but I’m cherishing every moment I get on stage -- it’s brilliant for me and long may it continue!”
Smith, beaten in his fourth European Tour final, had earlier produced wins over Cameron Menzies, Josh Rock and Nathan Aspinall before defeating Krzysztof Ratajski 7-5 in the semi-finals.
“I’m absolutely gutted, but fair play to Gezzy, the better man won,” said Smith.
He continued: “It’s fine margins. You’re playing the best players in the world -- if you don’t hit your doubles, you’re going to get punished.
“The crowd was absolutely amazing. Thank you for turning up all weekend, you were brilliant."
The PDC ProTour season resumes in Milton Keynes on the 27th of April.
Results
Last 16
Krzysztof Ratajski 2-6 Joe Cullen
Danny Noppert 6-4 Niko Springer
Nathan Aspinall 6-3 James Wade
Ross Smith 6-5 Josh Rock
Michael van Gerwen 6-5 Jermaine Wattimena
Wessel Nijman 6-3 Stephen Bunting
Martin Schindler 6-1 Jonny Clayton
Gerwyn Price 6-4 Chris Dobey
Quarter-finals
Krzysztof Ratajski 6-5 Danny Noppert
Ross Smith 6-4 Nathan Aspinall
Wessel Nijman 6-2 Michael van Gerwen
Gerwyn Price 6-5 Martin Schindler
Semi-finals
Ross Smith 7-5 Krzysztof Ratajski
Gerwyn Price 7-4 Wessel Nijman
Final
Gerwyn Price 8-6 Ross Smith