HUDSON — In only his fourth summer playing competitive golf, Ryan Kohler acknowledges he's still learning.

At the U.S. Amateur Public Links Championship in Utah last month, the first-time qualifier acquired his sea legs competing against the nation's elite amateur players. And on Thursday at the New Hampshire Golf Association Stroke Play Championship, the 28-year-old Spofford resident learned that it's difficult to play with a big lead.

Starting the 36-hole final day with a five-stroke cushion at 9-under par, Kohler went in reverse with rounds of 73-74 but held on for a three-stroke victory over James Pleat and D.J. Lantz at Green Meadow Golf Club.

With his 6-under 282 total on Green Meadow's Jungle Course, Kohler earned his first NHGA individual title. A member at Walpole's Hooper Golf Club who plays most of his golf at Brattleboro (Vt.) Country Club, Kohler took up golf in 2007 after graduating from Keene State, where he pitched for the baseball team. He started playing tournaments in 2009 and was an NHGA State Amateur semifinalist last year.

Despite ending in victory, Kohler's experience as a front-runner Thursday was no cakewalk.

“It's just tough to not play defensive, and it's hard to go out the same way you did the first couple days,” said the self-employed graphic designer, who opened with rounds of 69-66.

Five ahead of Pleat to start the last day, Kohler led Portsmouth's Craig Steckowych by the same margin after a 1-over-par third round and Steckowych's morning 67. But by early in the back nine of the final round, Kohler's lead had evaporated.

After a 2-over-par front nine dropped him to 6 under, Kohler parred No. 10 but stood on the 11th tee tied with Lantz, who was playing two holes ahead. A Lake Sunapee Country Club golfer who was runner-up at the State Am last month, Lantz had started the final round at even par but birdied half of the first dozen holes, including three in a row at Nos. 10-12, to draw even.

With a 10-foot birdie at No. 12, a dogleg-left par-4, Kohler regained the lead, and shortly thereafter Lantz ran into trouble at the par-4 15th. After driving left behind a tree, Lantz's screaming recovery shot caught timber, ricocheted backward and struck the golfer in the waist, resulting in a one-stroke penalty, not to mention a mild welt. A triple bogey dropped Lantz to 3 under, where he would finish after three closing pars.

“The wind was out of my sails after I made triple,” he said.

With a four-stroke lead over Lantz and Pleat, however, Kohler bogeyed No. 14 and like Lantz drove left into trees on No. 15. After pitching out into the left rough, his third shot came up short of the green. Meanwhile Pleat, a 21-year-old Nashua Country Club golfer, stuck his approach shot 4 feet from the hole.

After Kohler's ensuing chip stopped 8 feet short, the potential for a three-shot swing — and a tie between Pleat and Kohler — existed. But Kohler drained his bogey putt while Pleat missed his short birdie try.

“I thought it was going to break right, and then I looked at it from behind the hole and it looked like it might break left,” said Pleat, a senior-to-be at Dartmouth College. “But I still played it a little bit to break right and it didn't, and I kind of hit it a little too hard.”

With his lead two strokes, Kohler drained a clutch 25-foot birdie putt on No. 16, while Pleat lipped out a slick, downhill 5-footer.

“I tried to visualize it going into the hole,” Kohler said of the sharp, right-to-left breaker. “I got a little lucky on that one.”

After both players parred No. 17, Kohler drove into the right rough on the par-5 18th. Seeking to keep his ball below some nearby branches, he topped his 3-wood second shot into a downhill lie in the rough, 160 yards from a green perched atop a steep hill.

With an 8-iron, however, Kohler stuck his approach within 12 feet of the hole and clinched the title with a two-putt par.

With rounds of 71-69-74-71, Pleat posted his second consecutive top-five finish at the Stroke Play. Lantz shot 72-71-73-69.

Bedford's Jake Nutter, a Manchester Country Club player, finished fourth at 2-under 286, while State Am champion Joe Leavitt closed with 65 to share fifth at 287 with Steckowych, who shot a final-round 74.