McLachlin, in his second season on the PGA TOUR, recovered from trouble time after time to card 14 pars, three bogeys and a birdie on the 18th to finish the tourney at 18-under 270.
It feels like it has been a lifetime coming. It has been a dream of mine since I was about 12, said McLachlin, 29, who grew up in Hawaii and played at UCLA. This is a huge stepping stone for me.
The 29-year-old tied the course record with a 10-under 62 on Friday and set a 54-hole record at 20-under at the 7,472-yard Montreux Golf & Country Club near Lake Tahoe. But he had to scramble his way to the $540,000 winners check after hitting only four greens in regulation for the day. Brian Davis and John Rollins tied for second at 11-under 277.
Englands Davis trailed by only four strokes with five holes to go but had a double bogey and two bogeys down the stretch to shoot a 75. A shot back tied for fourth were Martin Laird (66), Harrison Frazar (69), Eric Axley (69) and Ryan Palmer (70).
On Sunday, McLachlin hit only one of his first 10 greens'only five for the round'but relied on his wedge and putter to save par, including a 12-footer after he had driven into the rough behind large pine trees on the par-4 fifth and a 9-footer after blasting out of a greenside bunker on the sixth.
McLachlin started the day with a six-stroke lead over Davis, but slipped back to four when Davis chipped in out of a bunker on the par-5 11th to get to 15-under and McLachlin missed a 6-foot birdie attempt to remain at 19-under.
The leader was in trouble again on the par-3 12th when his tee shot went in a waste area 20 yards right and short of the green but again managed to chip out of the pine needles to within 15 feet and make the putt. He also chipped out of a greenside bunker on No. 13 to 8 feet then rolled it in.
His lead grew to six again when Davis double-bogeyed after he took two shots to get out of a bunker at No. 14, while McLachlin two-putted for par from 12 feet.
McLachlins drive hit a tree and landed in a pond on the 636-yard, par-5 17th, but his 200-yard fourth shot made the back of the green and he two-putted from 60 feet for a bogey. He putted 15 feet for birdie on the 18th to join four others who claimed their first PGA wins at Reno'Notah Begay III (1998), Chris Riley (2002), Vaughn Taylor (2004) and Will MacKenzie (2006).
Brian was putting the heat on and I was feeling it. I was just gutting it out, McLachlin said. I didnt have much in the tank. It was all I had. Im pretty spent right now.
The closest McLachlin had come to winning on the PGA TOUR before was a tie for fifth in May at the AT&T Classic.
With the top 50 golfers in the world playing at the Bridgestone Invitational in Ohio, McLachlin entered the week ranked 98th on the money list, but the $540,000 first-place check at Reno gives him $1.28 million on the year and should push him at least inside the top 70. It also ensures him a spot in next weeks PGA Championship, his first major since he qualified for the U.S. Open in 2004.
Last year on the Nationwide Tour, McLachlin led the National Mining Association Pete Dye Classic by seven strokes entering the final round, but shot a final-round 77 to finish tied for fourth.
A similar scenario was possible on Sunday without his heroics around the greens. From 60 feet away on the 220-yard par-3 No. 7, he chipped to within 4 feet and made the putt then dropped a 6-footer after chipping from 50 feet on the par-4 No. 8.
With the wind swirling on the downhill, 616-yard, par-5 No. 9, his attempt to layup safe with his second shot landed on the side of a hill in six-inch deep rough 85 yards short of the pin. But again he chipped onto the fringe within 15 feet and two putted for par to make the turn at even-par 36.
The streak of par saves ended on the 494-par, par-5 10th when he hit in a bunker behind the green and missed a 12-footer for par.