Price produced his fourth perfect leg of 2022 during a 17-11 win over Dutchman Danny Noppert.
Earlier in the night, Van Gerwen enjoyed a late surge to deny 2020 champion Dimitri Van den Bergh 17-14.
On a thrilling night of tungsten action, it was the Iceman who stole the show after registering the first nine-dart leg at the event since Gary Anderson's effort in 2018.
UK Open winner Noppert was able to land three ton-plus checkouts to threaten a comeback win, but Price seemed unfazed by the challenged as he completed a convincing victory to storm into his first Matchplay final.
The newly crowned world number one was on top form as he produced an 11-darter and a 107 finish on his way to a 6-4 lead.
The 37-year-old then went on to land a history-making nine-darter to become the first PDC competitor to hit four televised perfect legs in a calendar year.
Price moved 10-5 ahead before Noppert fought back with a run of three straight legs. However, that run was quickly followed by a resurgence from the Welshman, who completed an impressive win.
"I felt brilliant for most of that game," admitted Price, who averaged 102.37 and fired in 13 maximums to become the second Welshman along with Richie Burnett to reach a World Matchplay final.
"I'm so glad the nine-darter went in, but it probably put me under pressure, because I know a lot of people who hit nine-darters go on to lose the game. Thankfully that didn't happen!
"I was hoping to go back-to-back, but it's good for the crowd and it's good for my confidence, especially at the Winter Gardens.
"The crowd on right on top of you, it's brilliant. It's a great atmosphere."
In the earlier match, Dimitri Van den Bergh raced to a 4-1 lead as he punished a sloppy start from Michael van Gerwen.
Despite this, the Belgium star was unable to hold off the three time world champion for long, as Van Gerwen slowly but surely sealed his spot in the final.
This will be the fourth final appearance for the Dutchman in Blackpool as he looks for a third title at the Winter Gardens.