Bradley took a one-stroke lead into the final round at TPC River Highlands and was never in real danger of being caught after making five birdies in his first 12 holes.

The 2011 PGA Championship winner gave the chasing pack a glimmer of hope with three bogeys in four holes from the 13th, but eventually signed for a closing 68 to finish 23-under-par.

The 37-year-old broke Kenny Perry's 2009 tournament record by a shot in front of adoring New England fans.

Fellow American Zac Blair surged through the field with a final-round 62 to finish 20-under-par alongside compatriot Brian Harman, who returned a second consecutive 64.

"This is for all the kids that grew up in New England, who got to sit through the winters and watch other people play golf," said Bradley, who was born in Vermont, one of the six states which make up the New England region.

"I just am so proud to win this tournament ... I'm so lucky and thankful to be from this New England area. I just can't believe it. This seems like a dream."

Bradley became the first New Englander to win the title since Connecticut's J.J. Henry in 2006.

World No.1 Scottie Scheffler (65), Patrick Cantlay (67) and Chez Reavie (71) shared fourth place at 19-under, with Rory McIlroy another shot back after a closing 64.

"I just am so proud to win this tournament ... I'm so lucky and thankful to be from this New England area. I just can't believe it. This seems like a dream." – Keegan Bradley.

"I got off to a hot start, which was nice and what I felt like I needed," McIlroy said after a round containing seven birdies and one bogey.

"I knew I was never going to win with the way Keegan was playing, but I felt like I probably needed a couple more birdies to finish top-five.

"Still, it's another good week and solid performance after a long run, and looking forward to a couple of weeks off."

But before heading into his break, the former World No.1 had time to be critical of the course which gave up eight rounds of 62 or better this week.

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"I don't particularly like when a tournament is like this," McIlroy added.

"Unfortunately, technology has passed this course by, right? It sort of has made it obsolete, especially as soft as it has been with a little bit of rain that we had."

Min Woo Lee carded a final-round three-under-67 to finish as the best Australian at 17-under and in a tie for ninth.

Lucas Herbert (68) at 15-under and Adam Scott (68) one further shot back both finished inside the top-20, with Cameron Davis (63) closing at 11-under and Jason Day (70) nine-under.