The world No.1 fired five birdies in a three-under par 69, following up his stunning course-record 61 on Saturday to finish with a 21-under par total of 267 - seven strokes in front of Webb Simpson and Patrick Rodgers who shared second on 274.
Australian Geoff Ogilvy shot a 68 in the final round to finish joint seventh, 10 shots back. McIlroy shattered the previous 72-hole tournament record set by Anthony Kim in 2008 by five strokes.
He became the first two-time winner of the event, in which he claimed the first of his 11 US PGA Tour titles back in 2010.
"Everything is firing on all cylinders for me," said McIlroy, who will now head across the Atlantic for the European Tour's PGA Championship at Wentworth and the Irish Open at Royal County Down.
McIlroy shook off a three-putt bogey at the second hole. By the time he bogeyed 17 he had built a seven-shot lead.
He birdied two par-fives on the front nine, the fifth and seventh, and birdied the 12th, 14th and 16th coming in.
At 12, he hit his approach shot 132 yards to two feet and tapped in for birdie.
He moved to 21-under with his birdie at 14 and at 16 landed his approach shot three feet from the pin and made that.
"The golf course sets up perfectly for me," said McIlroy, who rose to third in the US PGA Tour's FedEx Cup standings.
"With my length and the way I'm driving it, it's a big advantage around here and it showed this week."
Simpson started the day four shots behind McIlroy and closed with an even par 72.
Any hopes he had of catching McIlroy ended with a double bogey at the par-three sixth.
"He's our best player right now," Simpson said of McIlroy. "I wish more than anything I could have shot a couple-under on the front to make it more exciting.
"Just didn't have it today," he added.
Rodgers, playing on a sponsor's exemption, briefly moved within three strokes of McIlroy's lead after an eagle at the 10th and birdie at 11 but faded late in a 68.
He was in the water at 17 en route to a double bogey, unable to get the solo second place finish he needed to earn exemption for the rest of the PGA Tour season.
However, Rodgers did earn a berth in next week's Colonial.
"It has given me a lot of confidence moving forward," he said.
Gary Woodland, Robert Streb and Phil Mickelson tied for fourth on 12-under 276.
Share
