UPDATE 1-Golf-Niemann makes history for Chile with Greenbrier win

* Niemann becomes first Chilean to win on U.S. tour

* Strong back nine drives 20-year-old to victory

* Says he hopes to make Presidents Cup team

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* (Adds details, quotes)

Sept 15 (Reuters) - Joaquin Niemann got stronger as the day progressed to become the first Chilean to win on the PGA Tour, claiming a six-shot victory at the Greenbrier Classic in West Virginia on Sunday.

Tied at the ninth hole following a bogey, the 20-year-old, who had led most of the day, racked up six birdies on the back nine, including three in succession to close a six-under 64 round at White Sulphur Springs.

Not even a bogey at the 15th could halt his march as he won the opening tournament of the new PGA season at 21-under 259.

"It's crazy," said the emotional Niemann, who broke into tears when asked how it felt to become the first Chilean with a victory on the U.S. tour.

"I can't wait to go back home and celebrate with my friends.

"From the first day, I played with a lot of confidence ... My game was feeling great and mentally it was awesome, so I was just feeling like I was going to win this tournament."

He admitted he woke up thinking about the trophy and knew he had to turn his mind to the day ahead.

"I was just trying to think about anything else," Niemann said. "My caddie made me laugh to try to forget about it.

"The last couple of holes (as the birdies piled up) I was feeling great. I was really enjoying it."

He hoped the victory would earn him a call from Internationals captain Ernie Els for a possible captain's pick for the Presidents Cup against the United States in Australia in December.

"Being on the Presidents Cup, it's just a dream," Niemann said. "It's a really good team this year. There's a lot of good players fighting for spots. This win definitely helps."

Tom Hoge, who along with Richy Werenski had chased Niemann all afternoon, wound up second at 15-under after a closing 65.

Werenski (69), Brian Harman (65), Harris English (67) and Nate Lashley (69) were another shot back.

Playing for the third time in his career at Old White TPC, Niemann had begun the day with a two-stroke lead over Werenski, Lashley and Robby Shelton.

Hoge fired up with birdies on five of his first eight holes but three bogeys in his next seven holes ended his threat.

The win, complete with fist pumps, brought out a new side to Niemann.

"Normally I'm not really too excited," he said. "Like normally I don't do fist pumps.

"Just making those putts on the last three holes was unbelievable." (Reporting by Gene Cherry in Raleigh, North Carolina, editing by Pritha Sarkar / Ian Ransom)