Lydia Ko has become the youngest woman to win a major golf title and her coach says it is a milestone in the young golfer's career.
Ko's impressive eight-under-par final round took her to 16 under for the championship, six shots better than American Lexi Thompson.
World No.2 Ko carded eight birdies with no dropped shots, winding up her closing round with birdies on her last two holes.
Ko's swing coach David Leadbetter told Morning Report she was well prepared, but there was a lot more pressure on her playing for a major title.
"Majors are really the pinnacle of men's and women's tours, and so if you're going to win a major, you've got the best fields on the toughest golf courses."
The New Zealand golfer Lydia Ko has become the youngest woman to win a major, carding a 63 to claim the Evian Championship in France.
Thompson had led Ko by three shots during the front nine, but the New Zealand teenager turned the title race into a cake walk with eight birdies and no dropped shots.
"To finish with two birdies, finish on the last 72nd hole, with a birdie, it doesn't happen often," Ko told the LPGA.
"It's definitely one of the top rounds of my whole entire life, and I'm sure it will be in my career."
At 18 years, four months and 20 days old, Ko is six months younger than Morgan Pressel, the previous youngest major champion, when she won the 2007 Kraft Nabisco Championship.
"It's amazing that I can leave my name... a little bit in the history books," said Ko. "Winning at any age is amazing in a major, all players want to peak at their best at a major. To say that I'm the youngest in history for now, it's so cool."
Ko's final round was the lowest by a winner of a women's major, surpassing the 64 Karen Stupples carded when triumphing at the 2004 British Open.
South Korea's Lee Mi-hyang had begun the day at the head of a packed leaderboard on 10 under, one shot clear of Thompson.
Thompson's challenge faded after she moved three shots ahead of Ko during the front nine.
"I struggled on the back," Thompson said. "I kind of lost my tee ball and didn't hit good iron shots, and it's kind of hard to beat somebody that shoots 63."