Trump secured a break of 82 en route to a 2-0 lead, and although his opponent reeled off three frames on the bounce to sneak ahead, the 25-year-old quickly wrestled back the advantage to stand one away from victory at 5-3.
Breaks of 61 and 58 then drew Robertson level ahead in the topsy-turvy contest, before Trump found a 67 to win the decider.
Neil Robertson beat Matt Selt, pulling clear from 3-3 with two breaks of 70 and one of 75 to win 6-3.
"Matt is a much better player than his ranking suggests and he played well today," said Robertson. "We are good friends so we know each other's games well. It was a good match, the big turning point was the eighth frame to go 5-3 up."