Hideki Matsuyama tied the course record at Firestone Country Club with a nine-under final round of 61 on Sunday to win the WGC-Bridgestone Invitational, his fifth title on the PGA Tour.
After starting the final round two shots back, Matsuyama first jumped into a share of the lead with an eagle on the par-five second and a birdie on the par-four third.
He later added six birdies to complete a stunning bogey-free round and blow the rest of the field away, finishing five shots clear of runner-up Zach Johnson.
Japanese star Matsuyama, who entered the week ranked third in the world, now has three PGA Tour wins this season.
With a signature pause at the top of his back swing, Matsuyama posed an intimidating figure with long drives and accurate iron shots in Akron, Ohio and he looks ready to contend again for a first major win next week at the PGA Championship.
Johnson was a distant second at 11 under after firing a two-under 68 on Sunday, having gotten the better of both Rory McIlroy and Thomas Pieters over the weekend in mismatched pairings. Despite his lack of length off the tee, Johnson drained enough putts to contend in another big event.
Charley Hoffman, fresh off a runner-up finish last week at the Canadian Open, was third at 10 under.
Hoffman was one of the few to go for the green on the long, difficult par-five 16th, and decided to take the risk because he was "tired of finishing second".
Pieters started the final round tied for the lead, but putting woes led to a disappointing one-over 71 Sunday. He finished fourth at eight under.
Speaking of putting woes, McIlroy bombed his driver all week long, but really struggled to get the ball into the hole. He shot a one-under 69 on Sunday to finish tied fifth at seven under.