I'm truly humbled: British Open winner Zach Johnson

PGA's Zach Johnson on winning the British Open

Fresh off his second major golf title, Zach Johnson said Wednesday he's still in a daze from his win at St. Andrews at the 144th British Open. Johnson won the Masters in 2007.

The 39-year-old, who grew up in Cedar Rapids, Iowa, joins an elite group of golfers, including Jack Nicklaus, Tiger Woods, Sam Snead, Seve Ballesteros and Nick Faldo as the only players to win both a Green Jacket and a Claret Jug on the Old Course.

"I'm overcome with honor," Johnson told CNBC's "Squawk Box" in an interview. "To be associated with that history and that part of golf is truly humbling."

Johnson's win came in dramatic fashion after a five-day battle through wind and rain that sent the tournament into an extra day.

Read MoreDid Jordan Spieth hit a $120 million bogey?

The victory has moved Johnson to No. 12 in the world, earning him $1.8 million in prize money to add to his $37 million in career winnings.

But for the veteran golfer, he said it's never been about the money. "It's not my motivation and never has been."

Zach Johnson, British Open winner with his wife, Kim Barclay, and kids, Will, Wyatt and Abby Jane.
Photo: Grace Photography

After the Open, Johnson headed home to St. Simons Island, Georgia, where he lives with his wife, Kim Barclay, and their three kids: Will, Wyatt and Abby Jane. He provided CNBC with photos of his homecoming with the trophy.

"I haven't even watched it yet," said Johnson of the tournament. "I have it DVR'd."

When he does get a chance to watch it, he'll see himself close out his fourth round at 15-under with a 30-foot birdie putt on the 18th hole, earning a spot in the four-hole playoff against Louis Oosthuizen and Marc Leishman.

Johnson capitalized quickly. "The first putt on the first playoff hole was huge," he said, giving him the momentum to beat Oosthuizen and Leishman and to capture his second major title and 12th PGA Tour victory.

"It turned out my way," he said, grinning.

In a sport that has been increasingly about the long game, Johnson attributes his success to the wedge. "The three wedges have always been part of my arsenal," he said. "I'm not going to reach a par 5 in two shots, so that's where I can make up some ground."

Jordan Spieth finished the tournament one shot out of the playoff after a par on the 18th—ending his chances of making a historic run at winning all four majors in the same year. He came into the British Open with victories at the Masters and the U.S. Open.

"He's just unbelievable in every aspect—on and off the course," Johnson said of Spieth.

CORRECTION: This version corrects that some of the two-time champions played on a British Open course other than St. Andrews.