World Number One: "I showed how well I can play when my back's up against the wall"
Cullen put himself in pole position to oust the tournament favourite when taking a 2-1 lead in the best of five encounter, but the Welshman reeled off six consecutive legs .to seal a stunning comeback and earn himself a quarter-final date with Latvian Madars Razma.
Price has since shortened into 2/1 from 7/2 with BoyleSports to win a second World Grand Prix title, with five-time champion Michael van Gerwen rated his main danger at 3/1 ahead of a last-eight clash with Chris Dobey.
"I'm relieved because it was a tough game and I bombed the third set," Price told BoyleSports after the match. "I put myself under a lot of pressure and sometimes that's when I find some of my best darts.
"I showed in the last two sets how well I can play when my back's up against the wall, so I feel I'm a deserved winner. I just wish I could play that well from the word go."
A first-time winner of the event however is now an odds-on shot at 8/11, with 4/1 third favourite Peter Wright headleading six candidates hoping to be crowned BoyleSports World Grand Prix champion for the first time on Sunday.
Nathan Aspinall is now a 7/1 shot from his pre-tournament price of 40/1, while his quarter-final opponent Martin Lukeman has sunk into 33/1 from 250/1 after knocking out James Wade and Ross Smith.
Lawrence Lyons, spokesperson for BoyleSports, said: "Six of the eight left in the field are hoping to shed their maiden tag at the BoyleSports World Grand Prix, but Gerwyn Price would be virtually unplayable if he reproduces the form of his last two sets against Joe Cullen.
"It's no surprise that his odds are continuing to shrink as the majority of punters have been on board from the start and they haven’t seen anything yet to change their minds."
BoyleSports World Grand Prix
Outright Winner Odds
2/1 Gerwyn Price
3/1 Michael Van Gerwen
4/1 Peter Wright
11/2 Dimitri van den Bergh
7/1 Nathan Aspinall
20/1 Chris Dobey
33/1 Madars Razma
33/1 Martin Lukeman
Odds courtesy boylesports.com and correct at time of writing. Subject to fluctuation.