Perry's win at the Warwick Hills Golf & Country Club was his second this season.
The 47-year-old tour veteran finished at 19-under-par 269, a stroke ahead of Woody Austin and Bubba Watson.
Austin (68) and Watson (68) both had a chance to force a playoff, but Austin bogeyed the last hole and Watson missed a 12-foot birdie attempt.
"You need to make as many birdies as you can make," Perry said. "I got in at 19-under and I still didn't think it was going to be enough. I was fortunate enough to get it done."
Perry collected $900,000 for the win.
Bob Tway (65), Matt Jones (67) and Ken Duke (67) tied for fourth place at 17-under-par 271.
Daniel Chopra, the leader after three rounds, slipped to a 3-over 75 and finished in a tie for 17th.
Perry's other victory this year was at The Memorial in Dublin, Ohio, June 1.
Benedict Cumberbatch's dramatic reading of R. Kelly lyrics is just what you need
Gal Gadot cast as Wonder Woman for 'Batman vs. Superman'