The 26-year-old Welshman secured his second major ranking title of his career after a superb day of action in Furth, Germany.
White, who won the Indian Open – his first ranking title in 2015, beat world number Mark Selby in the last 16 round 4-1 before beating Mitchell Mann in the semi-finals.
White made a strong start to the final winning the opening two frames. Murphy pulled one back but White edged closer to the winning line with a break of 83 in the fourth frame.
The fifth frame saw White almost clinch the contest but missed a tough final black along the cushion, leaving it for Murphy to make it 3-2.
But White kept his composure in the next frame and secured the 4-2 victory with a break of 97.
It was another night of frustration for Murphy who once again missed out on the winning a world ranking title after losing the China Championship final to Luca Brecel last Tuesday.
The Paul Hunter Classic is is in memory of Paul Hunter who died of cancer in 2006. Hunter made great strides in the game winning three Masters titles and was one of the best in his generation to have played the game.
White, who burst onto the scene in 2013 by reaching the quarter-finals of the World Championship, won £20,000.