New Zealand's Lydia Ko celebrates

New Zealand's prime minister led the congratulations Monday after 18-year-old Lydia Ko made golfing history as the youngest winner of a women's major title.

"Amazing stuff," tweeted John Key. "Congratulations on your win at the Evian Championship and becoming the youngest ever major winner in women's golf."

New Zealand's Ko also became the youngest player to claim the world number one ranking in February, when she was still 17, although she is now second behind Park In-bee.

And she holds the record as the youngest winner on the LPGA Tour with the first of her nine victories coming as a 15-year-old amateur at the 2012 Canadian Open.

Ko's legendary coach David Leadbetter described her final round of 63 at Evian, the best round of this year's tournament, as almost perfect.

"She hit basically every green. I think she missed two fairways, just by a yard or two and she putted phenomenally well.

"Her strategy was good -- it was her time basically."

"It was pretty much a perfect round of golf."