OWINGS MILLS, Md. -- For 70 holes, Bernhard Langer did everything necessary to win his fourth straight Constellation Senior Players Championship.

Unfortunately, his performance at Caves Valley will be remembered only for what happened after that.

Langer's uncharacteristic collapse on Nos. 17 and 18 paved the way for Scott McCarron to win his first major tournament on the PGA Tour Champions in sensational comeback fashion Sunday.

McCarron shot a bogey-free, 6-under 66 to make up a six-shot deficit and beat Langer and Brandt Jobe by a stroke.

"I've been working so hard for this," said McCarron, a 51-year-old Californian. "That was one of my goals this year, to win three events and one of them being a major. So I've got one more event to go."

McCarron's victory at the Allianz Championship in February wasn't nearly as exciting as this one, which came to fruition because Langer came apart just when it seemed he was well on his way to making history.

Seeking his third major win of the year, the 59-year German had a one-shot lead before dropping his tee shot in the water on No. 17. After taking the one-shot penalty, he missed a 4-footer and had to settle for a double bogey.

Playing in the twosome ahead of Langer and Jobe, McCarron didn't need to see the leaderboard to realize what happened.

"It wasn't until I heard the fans up there in the cheap seats when Langer hit it in the water did I know that I might have a chance," McCarron said.

On 18, Langer lipped out a 6-foot birdie putt that would have forced a playoff.

"I thought I hit a really good putt," he said. "But the big issue was 17, hitting a horrible shot there and then missing for bogey. That was the killer."

He finished with a 73 that included only two birdies.

Langer was trying to become the first player in the history of the senior tour to win the same major four years in a row. The run began in 2014 at the Fox Chapel Golf Club in Pittsburgh, continued in 2015 at the Belmont Country Club in Massachusetts and stayed alive last year at the Philadelphia Cricket Club.

And now it's over.

"This is going to hurt for a little while because it was within my grasp to win the championship," Langer said. "All I had to do was come home in even par more or less. Twenty under would have done it. But it's easier said than done."

Langer started the day with a one-shot lead over Jobe, with McCarron a distant third at 12 under.

After Jobe birdied No. 1 to pull into a tie atop the leaderboard, Langer answered with birdies at Nos. 2 and 5 and went up by three shots when Jobe bogeyed 6.

But Langer didn't get another birdie the rest of the way. After his lamentable round was over, he looked back at what he did wrong -- rather than what put him in position to win.

"At 17, I hit it exactly where I didn't want to hit it -- in the water," Langer said. "Anywhere else, you know, left, short, long, you've got a chance. Out of the water, you don't. And I didn't make a putt all day."

McCarron got into contention with four straight birdies on the front nine. He finished with eight straight pars, which was good enough to earn him $420,000, his biggest payday on the 50-and-over tour.

Miguel Angel Jimenez shot a 66 to finish fourth at 16 under, and Steve Flesch (68) was fifth at 13 under.