Lydia Ko has broken records throughout her golfing career so it seems fitting the Kiwi has become the youngest female player to crack the US$1 million mark in LPGA Tour earnings.

At 17 years, two months and 26 days, Ko claimed the Marathon Classic and the US$210,000 (NZD $241,411) winner's cheque in Ohio on the LPGA Tour today and knocked Lexi Thompson (18 years, seven months and five days) off her perch as the youngest player to make it to a million.

Ko has now banked US$1,061,019 (NZD $1,219,924) on tour this year during a sensational maiden campaign as a full-time professional that has seen her record seven top-five finishes, with two victories.

The North Shore product, ranked No 2 in the world, seems a lock for rookie of the year honours but she was made to sweat for her victory today after a late charge from Korea's So Yeun Ryo.


Ryo made birdies at 16 and 17 and joined Ko at 14-under but the New Zealander birdied the 18th to take the clubhouse lead at 15-under.

Ryo then had a chance to force a playoff but she pushed her birdie putt wide at the par-five 18th as she finished in second place at 14-under, while Ko, who fired a bogey-free six-under 65 during her final round, was left to celebrate.

"My heart was beating and So Yeun was obviously playing well today," Ko said in a television interview. "I thought she had a big chance of making the putt and for us to go to a playoff."

Ko began the day in fifth place, two strokes off the lead, but made three birdies on the front nine as she began her charge to victory.

"I hit the ball pretty well and I gave myself a lot of opportunities and that's what you've got to do. The greens here are quite small so when I hit the green you kind of have a good chance [to make birdie] and that's what I did today."

Ko's win has kept her in third place on the LPGA Tour's Race to the CME Globe Standings, while she has also closed the gap on world No 1 Stacy Lewis.

Ko has now won seven professional tournaments, four of which came when she was an amateur, and today's title marked her fourth LPGA Tour victory.

She has never missed a cut in a professional event.