DORAL, Fla. — Dustin Johnson might never escape the whispers about what led him to take a six-month leave of absence from golf that caused him to miss the final major of the year, the lucrative FedEx Cup playoffs and the Ryder Cup.

No one ever questioned his game.

He provided all the answers Sunday when he won the Cadillac Championship.

The power was evident on the monster tee shot he hit on the daunting 18th hole at Trump National Doral, so bold and pure that Johnson might have been the only one who never doubted it would clear the corner of the water and land safely in the fairway, setting up a routine par.

“I absolutely smashed it,” he said.

The putting comes and goes, but it arrived when he needed it: The 20-foot par putt from the fringe on the 11th hole to stay one shot behind. The 10-foot par save on the 14th hole that gave him his first lead of the tournament. The 15-foot birdie on the next hole to seize control.

Also back was the swagger.

Johnson made up a five-shot deficit against J.B. Holmes, stayed in the game when Masters champion Bubba Watson looked as though he might run away, and powered his way to a 69-69 weekend and a one-shot victory for his second World Golf Championship title.