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.