Once ranked as high as fourth in the world, Fowler has endured a torrid time on the golf course in recent years, resulting in him dropping outside the top 150 and missing out on qualification for the Masters in 2021 and 2022.
Fowler was also coming off a missed cut at last week's Shriners Children's Open - though a top-10 finish at the Fortinet Championship a month ago gave the American some belief that he was starting to turn things around.
And after opening with rounds of 67 and 63 at Narashino Country Club to grab a share of the lead after 36 holes, Fowler's good form continued on Saturday with another rock-solid four-under-par 66 to seize the outright lead heading into Sunday's final round.
Birdies at the second, where he nearly found the cup from the fairway, as well as the seventh, 10th and 13th holes ensured he kept the chasing pack at bay, and while he did suffer a blip with a bogey at the 15th, a superb closing birdie at the 18th saw him finish top of the pile on 14 under par.
"It's been a while since I've been in this situation," Fowler said.
"Obviously (I) remember being in those situations before. But no, it will be tough tomorrow."
"(I've) definitely had some tough times the last few years, but I always knew it was there.
"It was always just a fine line - a shot or two here or there. Just nice to kind of see it starting to build momentum and confidence and the ball rolling the right direction."
Fowler is likely to face some stiff competition on Sunday, with former PGA champion Keegan Bradley lying just one shot behind after matching his 66.
Andrew Putnam, who shared the lead with Fowler overnight, fell off the pace somewhat with a 68, but still finds himself just two shots back.
Perhaps the biggest threat could come from Viktor Hovland, who made his move with a superb 64 on Saturday to finish just three strokes behind.
At 10 under, four adrift, the likes of Maverick McNealy, Cameron Champ and Hayden Buckley certainly can't be ruled out either.
Defending champion Hideki Matsuyama is certain to relinquish the title after a third-round 66 left him 10 shots off the pace.