It wasn't easy, but Lydia Ko validated her No. l spot in the Rolex Women's World Golf Rankings on Sunday, winning the ANA Inspiration in Rancho Mirage, Calif.
She needed and got plenty of help from Ariya Jutanugarn, who squandered her bid to become the first golfer from Thailand to win a major golf championship by blowing a two-stroke lead over the last three holes.
Ko, an 18-year-old from New Zealand, hit a brilliant approach on the 18th hole to set up a 2-foot birdie putt that gave her a one-stroke victory over Charley Hull of England and In Gee Chun of South Korea on Mission Hills Country Club's Dinah Shore Tournament Course.
Afterward, Ko made the traditional winner's leap into Poppie's Pond, part of Champions Lake that surrounds the 18th green.
"I kept making (par-saving) putts and kept telling myself I still had a chance," said Ko, who claimed her first major title last year in the Evian Championship in France and now has won two in a row.
"I didn't see a scoreboard until the 17th hole to see what the other girls were doing, and when I did, I knew I needed to make that birdie on the last hole to give myself a chance."
"It's an amazing feeling to be in this position. It's just a dream come true. Always thought it would be amazing to jump into Poppie's Pond."
And then she did.
A bogey-free, 3-under-par 69 in the final round left Ko with a 12-under-par total of 276.
Hull, also 18, birdied five of the last 10 holes for another 69, while Chun, the reigning U.S. Women's Open champion, closed with a 70 and had to lament her only bogey of the day on the 16th hole.
"I'm very happy with the way I played, especially on the back nine," said Hull, whose only pro victory came on the Ladies European Tour in the 2014 Lalla Meryem Cup. "It's nice to know that I can play well under pressure, making those birdies on the back nine, and I'm proud of the putt I hit on the last hole.
"I'm going to take some time off, but I can't wait for my next tournament. I'm going to keep working hard, and I'm excited for the rest of the season."
Jutanugarn, 20, whose only pro victory came in the 2013 Lalla Meryem Cup, built her two-shot lead by making birdies on four of five holes through No. 11 and seemed to be in control when she parred the next four holes.
Then it all fell apart, as she made bogeys on the 16th and 17th holes. She still had a chance on the par-5 18th, which is reachable in two shots for the big hitter that she is.
However, Jutanugarn pulled her tee shot into the water en route to another bogey that left her with a 71 and two strokes back in solo fourth.
Third-ranked Lexi Thompson, the 2014 ANA champion who took the 54-hole lead with an eagle on the 18th hole, made bogeys on two of the first three holes and didn't make a birdie all day.
However, she eagled the last hole again for a 73 that left her solo fifth, three strokes back.
Second-ranked Inbee Park of South Korea carded a 68 that left her four shots back. She tied for sixth with Gerina Piller, who had a double-bogey 6 on the second hole but finished her 70 with three straight birdies, and Caroline Masson of Germany and Sung Hyun Park of South Korea, who both had 71s.
Brooke Henderson of Canada, another 18-year-old, had four birdies on the back nine to post a 67 and finish at 281. She tied for 10th with So Yeon Ryu of South Korea, who carded a 69, Suzann Pettersen of Norway, who totaled 72, and Bo-Mee Lee of South Korea, who came in at 70.
Fourth-ranked Stacy Lewis closed with a 72 and finished in a disappointing tie for 18th.