SPRINGFIELD-Jimmy Walker said he never would have dreamed after missing the British Open cut two weeks ago that he would be the next man to hoist a major golf trophy.

But the 37-year-old American pulled off the astonishing feat Sunday at the PGA Championship, sloshing 36 holes across soggy Baltusrol and outdueling top-ranked defending champion Jason Day down the stretch to win. "It's surreal," Walker said. "I just had not quite played as well as I would have liked to this year. Just to be in it and be there and have a chance and then to finish it off is just so gratifying. It's amazing."

Walker had not won since the US PGA Texas Open 16 months ago, falling from the top 10 to 48th in the world rankings. But when he shared 21st at the Canadian Open between the British Open and PGA, Walker had an epiphany. "Some stuff kind of clicked last week, literally in the last like nine holes," Walker said. "Everything felt good. I kept it going. Finished off the round. Finished off the nine holes. It felt big to me. Like everything worked, like my head was there. I was in every shot."

In the final round, Walker chipped in from 45 yards to birdie the 10th hole. When Day answered with a 22-foot birdie at the 11th, Walker rolled in a 30-footer on the same hole minutes later to reclaim a two-shot lead. Walker sank an eight-foot birdie putt at 17 only to have Day eagle the 18th, forcing Walker to save par from the greenside rough. He sank a tense 3-foot par putt and the Wanamaker Trophy was his, along with $1.8 million (1.6 million euros).

"Incredible finish, it really was. Just puts a smile on my face," Walker said. "Has not even really sunk in yet. It has been a whirlwind. But it's awesome." And totally unexpected, Walker said. I wouldn't have called this, but it's huge," Walker said. "It's nice to get in the position and keep the hammer down and keep making birdies and keep playing well. Kept working hard. It's just nice to see it pay off."

It helped that Baltusrol was where he met his caddie, Andy Sanders, at a US Amateur practice round. "We've been together a long time. And to win our sixth event, first major, here where we met, that's just cool," Walker said. "It's special for both of us. It's pretty emotional. He grinded it out this week. He did a great job. He reads putts great. Didn't let me hit a shot until I was ready. Made sure everything was good. We did a great job this week communicating and talking shots. Just we were in sync."

Adding to the chemistry -- Day is another of Walker's pals as the two park beside each other at events in their motor homes. "We're the bus guys out here," Walker said. "We park next to each other every week and we see each other and we're good friends." Day is a happy member of the bus buddies club. "Me and him have been like bus partners for awhile now," Day said.

 "We text each other all the time about him getting a new bus and I'm showing him mine. We're always parked right next to each other, always hanging out. We see each other all the time. He's a top bloke."

Walker joined Masters winner Danny Willett of England, British Open champion Henrik Stenson of Sweden and fellow American Dustin Johnson, the US Open winner, as the first foursome of first-time major winners in the same year since 2011. "It shows that everybody is really good and everybody's got a chance to win," Walker said. "It's just a matter of time. That's what I felt about myself and winning something like this."