Everything was new to In Gee Chun when she came to the United States to play at the U.S. Women’s Open golf tournament in Lancaster, Pennsylvania this past week: a new major tournament, a new course, and a new caddy.

Chun, 20, embraced all of the novelty and earned herself a new title: the 2015 U.S. Women’s Open Champion.

“Everything I faced and I did here was completely new,” Chun said. “So all I did was enjoy the new stuff … I enjoyed it and had a lot of fun.”  Chun credited the supportive American fans whose clapping put her “in the great rhythm of play, and I enjoyed that rhythm.”

The South Korean native, who had never before played in a U.S. Open, came from behind on the back nine to win the tournament.

GALLERY: CLICK HERE TO SEE OUR LITITZDAILYNEWS.COM FINAL ROUND PHOTOS

Amy Yang took the lead during the third round on Saturday, and stayed there with solid drives and well-placed putts through the first fourteen holes on Sunday, when things got tough for her in the rough.

“The rough is very sticky out there,” said Yang in an interview with LititzDailyNews.com after the tournament ended. “Also the greens are very ‘slopey’ and tough too.” The decision was made Saturday night to not cut any of the rough on the course before the final round of play.

Chun’s Sunday birdie run on holes 15, 16, and 17 launched her to the top of the leader board, where she remained through the end of play.

Chun overtook Yang when she birdied the 428-yard, par-4 15th to drop to -7 for the tournament on the first day when the back nine of the course at Lancaster Country Club was shorter than the front nine.

Yang and Stacy Lewis were tied at -6 going into 16, where Chun had already birdied on on the 235-yard par 4 at 16, stretching her lead to three strokes. Yang made an eagle on 16, closing the gap.

On hole number 17, the par-3 set at 170 yards to be the second shortest hole of the day, Chun again birdied to reach -9, to stay two strokes ahead of Yang.

Chun’s approach shot on the 421-yard, par-4 18th hole came up short of the green to the left.  She chipped onto the green landing to the right and slightly above the center back-right hole location. Leading by only one stroke, Chun missed a 10-foot par putt high of the hole t hen tapped in to finished the tournament at -8.

In order to force a playoff, Yang, who was trailing in the final pairing with Lewis and watching from a distance as Chun putted, would need to make her par putt on the 18th green. With all eyes and lenses focused on her, Yang missed the putt and went on to bogey the hole.

Chun won by one stroke, and recorded a history-making 72-hole total of 272 to match the 72-hole scoring record by Hall of Fame golfers Annika Sorenstam (1996) and Juli Inkster (1999). Three other golfers have won the coveted U.S. Women’s Open trophy on their first try: Juli Inkster (199) Birdie Kim (2005), Kathy Cornelius (1956) and Patty Berg (1946).

Like the LititzDailyNews.com Facebook page for more exclusive US Women’s Open coverage and for breaking news. Follow LititzDailyNews.com on Twitter and on @LititzDailyNews on Instagram, where you can tag us in your photos for possible publication. Subscribe for FREE to receive stories by email to your inbox.