Kenseth wrested it with quick pit work on Lap 278. But each time Johnson was overtaken, he roared back with ease.
The complexion of the race changed abruptly after NASCAR threw a caution for debris 365 laps into the 400-lap race.
Biffle, Stewart, Ryan Newman and Kasey Kahne gambled by taking just right-side tires - a move that put them back on track ahead of the front-runners who took the conservative tack and changed all four.
Johnson's task was compounded after his crew had a miscue changing his left rear, and he exited the pits eighth.
The biggest wreck of the day followed moments later, when David Stremme got knocked into the inside wall, then spun around and drifted back up the track, his nose pointed into onrushing cars.
No one was injured in the melee that ensued. But things got more interesting from there.
Biffle led the field back to green, and Johnson, buried farther back, went on a tear.
He dived in between the lapped cars of Gordon and Martin Truex Jr., who respectfully eased off the gas to give him room, and squirted out in front. Meantime, Stewart gained ground on Biffle, snatching the lead with eight to go.
Johnson then whipped around Biffle to make it a two-man race.
It was Johnson's 42nd victory in 268 NASCAR Sprint Cup starts, which means he has won roughly every six races he has entered - a staggering statistic for a driver who competes in a 43-car field.
Asked afterward how he pulled this particular victory off, Johnson gave credit to his Chevrolet.
"Great racecar!" he said. "We had an awesome, awesome racecar!"
