Johnson snatches Classic win

The 31-year-old birdied the first extra hole, the 18th, to take the title after third-round leader Imada had found the water.

Johnson, whose two previous titles - including the Masters - also came in Georgia, carded a superb five-under-par 67 to force the play-off.

Johnson's chance for victory came when Imada fired his second shot on the par-five 18th into the water hazard just in front of the green.

"I admire (Imada's) courage in going for the shot," said Johnson. "I understand why he hit his shot.

"If it was a little bit right it may have carried on.

"We (then) thought about laying up but at the same time I had a perfect lie, perfect yardage. It was a pretty routine shot."

Camilo Villegas, Matt Kuchar and Troy Matteson finished tied for third at 12 under - three adrift of Johnson and Imada.