“This morning going to the course, I was kind of fist-pumping because I knew the weather was going to be [crappy],” said David Lingmerth. (Jonathan Ferrey/GETTY IMAGES)

The skies had cleared by the time David Lingmerth accepted the glass trophy for winning the Web.com Tour’s Neediest Kids Championship on Sunday, but the 25-year-old from Tranas, Sweden earned his first professional victory because of his ability to navigate the misty and cold final-round conditions at the TPC Potomac at Avenel Farm.

While other golfers struggled to gauge distances with the air heavy and greens soggy, Lingmerth flourished, carding a 66 on the par-70 course to finish the tournament at 8 under and beat runner-up Casey Wittenberg by a shot. With the $108,000 winner’s check, Lingmerth bolstered his bid to finish among the tour’s Top 25 money leaders and gain PGA Tour membership for next year, jumping to seventh on the list with three events left in the season.

“This morning going to the course, I was kind of fist-pumping because I knew the weather was going to be [crappy]” Lingmerth said. “I’ve kind of gotten Americanized a little bit, I have to say, but this is a good day in Sweden. I’m used to playing in this type of weather.”

Lingmerth led the tournament heading into the weekend but a forgettable third-round 74 stuck him playing three groups ahead of third-round leader Josh Persons on Sunday. Persons — a Monday qualifier — faded fast on the way to a 77 and Lingmerth jumped up the leader board on a day when the average score was more than a full stroke higher than any other round at 73.3.

The University of Arkansas graduate birdied five of his first 14 holes — three on tap-ins from two feet or closer — and held a three-shot lead for much of his back nine. But he had to sweat out the finish after bogeying No. 18.

Playing in the final group, Wittenberg was 3 over on his front nine, but he closed within one after hitting a 10-footer for birdie on the 16th hole. While Lingmerth stretched in the locker room and relied on attendants for updates, the tour’s leading money winner missed birdie putts to tie on each of the last two holes.

Wittenberg looked to the sky in disgust after leaving a 4-iron from 200 yards at the front of the green on 18, and then he hopped as his 40-foot putt slid off the right edge.

“It wasn’t like I had wedge in my hand [on 17 and 18] where you’re really licking your chops,” said Wittenberg, who played on the PGA Tour in 2009. “I did all the damage to myself there in the early part of the round. . . . If I could have gotten off to a little better start, I might have had a better chance.”

Lingmerth came to the United States to chase his golfing dream in 2006, starting his collegiate career at Division II West Florida. He turned pro two years ago and just missed earning his PGA Tour card last year when he placed 27th in the then-Nationwide Tour standings.

Coming into this week, the 5-foot-8, 175-pound Lingmerth had been scuffling with five missed cuts in his past six events, including three straight.

He said he felt comfortable at TPC Potomac right away because it rewards control over distance more than many Web.com Tour stops, and with the breakthrough victory, he’s moved closer to spending next year on the PGA Tour.

“I’ve never felt like I’ve gotten anything for free,” Lingmerth said. “I’ve had to work my way up through every level. Obviously, this is just another step that I’m proud to take.”