The rookie was in red-hot form as he overturned a seven-shot deficit to card a nine-under 61 around Hurtsbourne Country Club, enough to edge fellow American Paul Peterson by one stroke.
Mouw birdied the first three holes and added two more on seven and eight for a front-nine 30. He then birdied the tenth, 11th, 13th and 17th on the back nine in the lowest score in his brief PGA Tour career. It was just his 20th start on Tour.
"I was mentally ready for a playoff, and if it came to that, I was ready," Mouw told AP.
"But that wasn't the case and I'm just blessed to be the winner. I knew that if everything clicked and I did the right things, I could go pretty low. I'm just thrilled that it happened."
"I have job status for two more years and I get to use that to play some really good golf and try to win another golf tournament. But as for my life, it doesn't change my life very much."
DP World Tour player Manuel Elvira was third at seven under after a closing 66, while Kentucky native Vince Whaley (70) and David Skinns (70) followed at six under.
Kurt Kitayama came out firing at the 3M Open on Sunday, birdieing six of his first eight holes before holding his nerve down the stretch to secure his second career PGA Tour title.
Thorbjorn Olesen took over at the top of the 3M Open leaderboard on Friday after carding second-round 66 to lead by one shot over Jake Knapp heading into the weekend.
Canada's Adam Svensson fired the lowest round in the seven-year history of the 3M Open to open up a two-shot lead after Thursday's opening round in Minnesota.
Chan Kim has a four-stroke lead after the opening round of the ISCO Championship in Kentucky on Thursday.
