Hoffman missed the course record at the TPC Boston in Norton, Mass., by a stroke but matched the event's scoring record of 22-under 262.
"I actually didn't know how many birdies I had today," said Hoffman, who earned $1.35 million for his second PGA Tour victory. "The ball just kept going in the hole, and the few bad shots I hit, I got away with. It was a really fun day."
Tiger Woods birdied three of the last four holes for a 68 to finish tied for 11th at 10 under. Woods moved up to 51st in the FedEx Cup standings, earning one of 70 spots in this week's BMW Championship.
Phil Mickelson again could have passed Woods atop the world rankings but struggled on the back nine. He shot a 76 to slide into a share of 25th.