That left the 51-year-old Scot at eight-under 280, four strokes ahead of Mexico's Esteban Toledo who closed with a 69 on a blustery afternoon.
Montgomerie became the first player since American Hale Irwin (1996-1998) to successfully defend the Senior PGA Championship.
The Briton, one of the best players never to land a regular major title, won last year's Senior PGA at Harbor Shores in Michigan before claiming his second Champions Tour major two months later at the U.S. Senior Open.
"I'm just making up for lost time," a beaming Montgomerie told NBC Sports about his successful run in the blue riband senior events over the past 12 months.
"I spent 22 proper years trying to do this and three (wins) have come at the one time," said the Scot, who was a runner-up five times in regular majors during a glittering career that also yielded a record eight European Tour order of merit titles.
"It's a fantastic time I am having. The American crowd have embraced me and I've embraced them and I'm having fun out here. I think that's what it's all about. I enjoyed this layout."
Montgomerie never allowed his pursuers to get any closer than two shots on Sunday and he effectively secured victory with a sizzling run of five birdies in eight holes from the fifth.
"Finishing second is not that bad but Colin ... just an outstanding job he did today," said Toledo, a former professional boxer who birdied three of the first seven holes before his own title bid stalled.
"Four under par today is incredible. It's hard to catch up when somebody is playing really well. I put a little pressure on the front but ... then it kind of slipped away."
Woody Austin carded a 69 to finish alone in third place at three under, one stroke better than fellow Americans Brian Henninger (71) and Scott Verplank (71).
(Reporting by Mark Lamport-Stokes in Los Angeles; Editing by Gene Cherry)
Share
