The 23-year old claimed a three-shot victory at Mission Hills Country Club in California, breaking down in tears after she rolled in a 20-foot birdie putt on the 72nd green.
Ko, who is in just her second season on the LPGA Tour, extended her one-shot 54-hole lead to win by three over fellow South Korean, Mi Hyang Lee with American Lexi Thompson another shot back.
Ko, who won last year's Women’s Australian Open at the Kooyonga Golf Club in Adelaide on her way to the Rookie of the Year title, has been a standout performer in 2019.
Her major breakthrough in Rancho Mirage is her fourth LPGA Tour title and second in three weeks having won last month's Bank of Hope Founders Cup.
A brilliant amateur in Korea before turning professional in 2013, Ko performed with distinction on the Korean domestic LPGA circuit before gaining access to the US LPGA Tour through winning a jointly sanctioned event in 2017.
Jin Young Ko led the field in birdies and greens in regulation at the @ANAinspiration, a recipe for Major success.
During her final round, Ko birdied two of her final three holes to lock up her victory.
HIGHLIGHTS pic.twitter.com/Zh1qcGRs4J— LPGA (@LPGA) April 8, 2019
Ko's win at the Australian Open in her very first start as an LPGA Tour cardholder gave an indication that she was more than capable of adapting to golf and golf courses away from her homeland.
Already number 5 on the Rolex World Ranking, her victory today will take her higher, continuing one of the fastest rises in the game in recent times.
Ko has also developed remarkable consistency, this win being her 5th top three finish in six starts in 2019 to go with her 13 top ten finishes in 2018.
The USD$450,000 she earns for her victory today takes her earnings in 2019 past USD$1 million and it would appear there is a lot more to come.
While her victory appears comfortable on paper, the gap between Ko and Lee was just one when Ko bogeyed the 13th and 15th holes but she fought back with birdies at the 16th and 18th.
And with Lee unable to force the issue over the closing holes, the margin would be three.
Former winner, Lexi Thompson, closed quickly with a final nine of 32 and a round of 67 to finish alone in 3rd while Carlota Ciganda and In Kyung Kim tied for 4th one behind Ciganda.
Kim had been Ko’s nearest challenger through much of the opening nine holes today but a ball stuck in a tree at her 11th hole effectively ruined any chance she might have had of atoning for a disastrous 18-inch miss at the 72nd hole in 2012 which cost her victory that year.
Katherine Kirk led the Australians but after being in the mix for much of the opening 63 holes and looked as though she could contend when a spectacular bunker hole out at the par-4 6th moved her within 5 shots of Ko.
Tough bunker lie + uneven stance = No problem for @Katherine_Kirk1April 7, 2019
But Kirk backtracked with a final nine of 38 to finish in a share of 17th.
It was Kirk’s second-best finish in 12 appearances in the event but perhaps it is a case of what might have been.
Minjee Lee produced a good weekend after a slow start to finish one shot behind Kirk in 21st place while Sarah Jane Smith, in what is likely to be her last major before the arrival of her first child, made the weekend but finished well back.
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