The American carded a final day two-under 69 at Wilmington Country Club to finish 14-under and edge compatriot Scott Stallings by a stroke.
The triumph secured the 30-year-old a $2.7 million share of the $15 million tournament prize purse and stamps his ticket as the No. 2 seed for the Tour Championship at Atlanta’s East Lake Golf Club on Thursday.
Starting two shots behind No. 1 Scottie Scheffler, Cantlay will look to defend a second successive title following his wire-to-wire victory in the season-ending event last September.
“I’m in a really good spot,” Cantlay told reporters.
“It’ll be a little different type of a challenge this year, obviously, being two behind Scottie. He’s played a lot of great golf this year, so I expect the same. But it’s a golf course I really like, and I’m looking forward to the challenge.”
With the leading duo tied heading into the closing two holes, a thrilling climax saw Cantlay’s booming tee drive narrowly skip over a bunker and settle 63 yards from the hole.
“I thought hitting it on that line, it would for sure be in a bunker,” Cantlay said.
“Maybe one of the best breaks I’ve gotten coming down the stretch, and when you get a break like that, you need to pay it off, and fortunately I did.”
A superb approach left the world No. 3 with a short putt for birdie, and — as Stallings parred — Cantlay made no mistake to nudge ahead.
Having narrowly dodged the sand on the penultimate hole, fate caught up with Cantlay when his final tee shot dropped into a bunker over 150 yards from the pin. But the 30-year-old responded with what he dubbed as one of his best shots all week, slicing his exit shot onto the green.
Though a 48-foot birdie putt came up just short to deny the American a fairytale finish, Cantlay tapped home for par to retain the crown he won at Caves Valley in Maryland last year.
The win marks Cantlay’s second of the PGA Tour season following victory at the Zurich Classic in April. It may well have been more had it not been for a trio of runner-up finishes at the WM Phoenix Open, RBC Heritage and the Rocket Mortgage Classic, yet Cantlay is not hung up on near-misses.
“The thing I always remind myself of when I finish second or I’m close is Jack Nicklaus had more seconds in majors than he had wins,” he said.
“That stat will shock you considering he has the most majors ever. No one would ever say he couldn’t close or no one would say that he wilted under pressure, and yet he had more second places than anybody else.
“You can’t always control what other people around you do or where you get the right bounce or the wrong bounce. But putting yourself in contention time after time after time, the bounces are going to go your way and you’ll get your fair share of wins,” he added.
Scheffler and Xander Schauffele led the chasing pack to finish 11-under, but it was a catastrophic final round for world No. 8 Collin Morikawa.
Having shot 65 on Saturday, the two-time major winner had looked set for a strong finish but saw his hopes of a late charge dented by back-to-back bogeys at the third and fourth hole.
A birdie at the fifth saw the 25-year-old jump to joint-sixth place, but disaster struck at the par-four 11th hole when he four-putted for a double bogey.
Yet the nightmare was only just beginning, as Morikawa subsequently sent two shots into the water guarding the green on the 12th hole. A series of missed putts compounded the American’s woes, as he finally holed out for a 10-stroke quintuple bogey, the highest score he has ever holed on the PGA Tour.
Morikawa closed with six straight pars to card an eight-over 79, finishing tied for 44th. Despite his final round woes, the 2021 Open champion nonetheless qualified for Thursday’s Tour Championship, where he will start as the 20th-ranked seed of the 30-player field.