Mehta, who had yesterday defeated compatriot Pankaj Advani in the quarterfinals, continued his dream run by entering the summit clash of the 300,000-pound event.
He will take on Chinese sensation and World No.4 Ding Junhui later in the evening.
Continuing his great run, the Cali World Games gold medallist got the better of a tough and experienced World No.5 Maguire, winner of five ranking titles, in a contest that lasted close to three hours. He marked his progress with a break of 142.
"A couple of years ago, no-one would have imagined that an Indian player could win a ranking title, but now I'm only a match away," said Mehta.
"If I do win, I hope it will be a great thing for the sport in India," he added.
The highlight of the game was the final minutes of the decider frame where with just three balls left on the table, the players wrestled each other for long passages of play.
With scoreline in favour of Mehta at 61-35, the Indian committed a foul, which gave his opponent a five-point cushion. With 18 points remaining on the table and Mehta still comfortably positioned, Maguire resorted to tactical game that left the World No.72 frustrated.
Maguire decided just to touch the balls and not to pot them in order to induce Mehta into committing another foul.
Mehta, however, did not fall for his ploy and, after a while, potted blue and pink to seal the issue in his favour.
The Indian showed no signs of fatigue after last night's four-hour marathon against Advani.
It was Mehta who set the ball rolling with small breaks of 32 and 42 to pocket the first frame 84-0. He went on to win the next two frames 137-0 and 132-0 to take a commanding 3-0 lead.