DULUTH, Ga. — Zach Johnson is two-thirds of the way to the Georgia Slam.

OK, no such achievement exists, but anything seems possible for the Masters champion in the Peach State.

"Yeah, I'm not sure what it is," he said. "You know, for whatever reason, I've had success here."

Johnson won the AT&T Classic on Sunday, beating Ryuji Imada with a birdie on the first hole of a playoff.

Johnson, also the 2004 winner, closed with a 5-under 67 to match Imada (70) at 15-under 273 on the TPC Sugarloaf.

In the playoff on the par-5 18th, Johnson hit his second shot above the pin, then rolled a 60-footer for eagle within 5 inches of the hole. He now had his third PGA Tour victory, each of them coming in Georgia.

Imada could only offer a congratulatory handshake. His tee shot landed in the left-side rough and his 3-wood failed to clear the water.

Laying up was not an option, Imada thought, because with Johnson in the middle of the fairway, there seemed little chance his opponent would make par.

"I don't want to second-guess myself," Imada said. "If I laid up, it was going to be a tough shot regardless. The green on 18, front left, is pretty hard. I mean having a 15-footer for birdie, you know, your chances are not good."

Seeking to become just the third player from Japan to win on the PGA Tour, Imada lost a critical stroke with a drop that all but nullified his next approach.

For Johnson, scoring conditions the last four days were nothing like those at Augusta National, which endured bitterly cold wind in April when Johnson matched the highest score in Masters history at 1-over 289.