The 23-year-old had six birdies coming in as he rallied for the victory over a faltering Patrick Rodgers.
The 23-year-old had six birdies coming in as he rallied for the victory over a faltering Patrick Rodgers, punching his ticket to next week's British Open in the process.
"I don't even know what it means right now," said DeChambeau, who carded a final-round 65 for an 18-under par total of 266 at TPC Deere Run in Silvis, Illinois.
After starting the round four adrift, he finished one stroke in front of Rodgers, who started the day with a two-stroke lead but fell behind DeChambeau with a bogey at the par-five 17th and couldn't come up with a birdie at the last to force a playoff.
Rodgers signed for a 70 that put him in 267, alone in second and one shot in front of Wesley Bryan and Rick Lamb.
Bryan closed strong with a 64 and Lamp carded a 66.
DeChambeau was in the practice area, trying to stay warm for a possible playoff when Rodgers' challenge ended.
"I've just been working so hard my whole life to try and do this," the emotional player told a television interviewer.
"To finally have it happen at the John Deere -- where I started pretty much a couple of years ago -- is just incredible," added DeChambeau, who played the tournament on a sponsor's exemption in 2015.
DeChambeau had endured a series of disappointing finishes this season, including a missed cut on six-over at the US Open last month.
He played the front nine in level par after one birdie and one bogey, then put together three bursts of back-to-back birdies -- at 10-11, 13-14 and 17-18.
Rodgers was one-over through the first nine holes, but reasserted himself with birdies at 10, 12 and 13. A bogey at 14 was quickly followed by a birdie at 15 and the rough at the par-five 17th off the tee. He eventually found himself chipping from the green to get over a bunker and missed an eight-footer to save par.
DeChambeau said he felt the victory was something of a vindication of his unorthodox decision to play with irons and wedges of similar shaft length, which he believes is a scientifically sound approach.
"I think that's the true meaning behind what I try and do," he said. "I show everybody there's plenty of ways to do it and I like doing it my way and I feel comfortable doing it my way. Whatever way you want to do it out there, you can do it."