Trump was never ahead in the match until winning it as the left-hander fired in breaks of 66 and 121 before taking a tense deciding frame to reach his first ranking final of the season.
Despite the fireworks produced by the former world champion to turn the match around, Vafaei will be left to rue a missed opportunity in the final frame as he overran a positional shot before missing a tricky pink to leave his opponent among the balls.
Trump, having broken down earlier to present his Iranian opponent with a winning chance, this time made no mistake, defying a poor positional shot of his own to drop a key red into the middle pocket and leave Vafaei needing snookers.
Despite several good attempts, Vafaei could not rescue the situation and after scraping past a below-par Neil Robertson in the quarter-final on Friday, Trump got out of jail with some of his best snooker of the week to remain on course for the title.
"He played well, his game is very attacking so it puts you under a lot of pressure," admitted Trump. "When it went 5-3, all pressure kind of left me then; it was looking like he was going to win.
"To be honest he was much the better player today."
Vafaei was less inclined to suggest he was superior to Trump, but was nevertheless keen to take the positives with him to next week's event in Turkey.
"I am disappointed, because I didn't perform that well," said Vafaei. "I had my chances but didn't take them, as simple as that. He potted some unbelievable long balls, but I was 5-3 up.
"He deserved the victory, he was the better player today. I had a very good week, you have to see the positives."
Joe Perry awaits Trump in the final after he held firm to beat Jack Lisowski 6-5.
Lisowski, playing with the Ukrainian flag on his waistcoat, had staged an inspired comeback to beat Ali Carter in the quarter-finals but could not repeat that here, losing a decider which hinged on a safety battle which Perry won.
It's been a notable return to form from the veteran, who was 125/1 for the title at the start of the week having failed to advance past round two of a ranking tournament all season.
