Bryson DeChambeau celebrates after sinking a putt to win the Arnold Palmer Invitational golf tournament Sunday in Orlando, Fla. (AP photo)

ORLANDO, Fla. — The long ball helped Bryson DeChambeau outlast Lee Westwood on Sunday to win the Arnold Palmer Invitational, only the key shots were as much with his putter as his driver.

DeChambeau holed a 40-foot birdie putt on the front nine and a 50-foot par putt early on the back nine. He closed it out with a nervy 5-foot par putt for a 1-under 71 and a one-shot victory over the 47-year-old Westwood.

It matched the low score of the day, one of only three rounds under par in the toughest final round at Bay Hill in 41 years.

DeChambeau and Westwood were never separated by more than one shot over the final 15 holes, a fascinating duel of generations that came down to the last shot.

For the second straight day, DeChambeau revved up thousands of fans on the par-5 sixth hole by smashing driver over the lake and leaving himself 88 yards away on the 565-yard sixth hole. Westwood was 168 yards behind him, and raised both arms to jokingly mimic DeChambeau’s reaction from the day before. They both made birdie.

DeChambeau appeared to be in trouble on the 11th when he narrowly missed going in the water off the tee, caught a plugged lie in the front bunker and gouged it out to 50 feet. He made that for par to stay ahead by one.

Westwood tied him with a 30-foot birdie putt on the par-5 12th, only to give it back with a three-putt on the 14th. The tournament turned on the par-5 16th, where it was Westwood who had the advantage.

DeChambeau’s drive went up against the lip of a bunker and he had to lay up short of the water. Westwood had 158 yards and hit a poor short iron that came up short of the green. He chipped nicely, except that it rolled out 6 feet by the hole on the lightning-quick greens and he missed the birdie for a chance to tie.

DeChambeau took the one-shot lead to the 18th and hit his most important drive of the day — in the fairway. The tee shot by Westwood, who shot 73, settled in a divot, and he did well to get it on the green and two-putt from 65 feet. DeChambeau’s birdie putt slid 5 feet past and he shook his arms in celebration when the par putt dropped.

Corey Conners stayed in the mix until the very end. The Canadian holed a 15-foot eagle putt on the 16th to get within one shot, only to find a bunker on the par-3 17th and miss a 6-foot par putt. With a bogey on the final hole, he shot 74 to finish alone in third.