Ko, as has become her custom, set another swag of records today in holding off Korean Amy Yang by two shots to win on the fabled Royal Melbourne Composite Course.
The win, Ko's sixth on the LPGA Tour and fourth national championship after two in Canada and one in her native New Zealand, will help consolidate her position atop the Rolex Rankings.
But it was the method by which she lived coach David Leadbetter's instructions to be taller, cooler and smarter that made most who witnessed sense it won't be anywhere near her last.
"We've been working on my swing and "˜be tall' is the part in my swing where I shouldn't dip my head and I would say my height is 5'3".7, so he said "˜Lydia, you were 4'11" the other day'.
"He told me to keep my height and said (I was) 5'3".8' and I was like, "˜Ok, I'm getting taller'. We were talking about that in the sense of "˜be tall'.
"Be cool was because we discussed that it was going to be hot and also be cool in the head too, be smart, play safe when you need to and then be aggressive.
"Play smart was really the biggest thing he told me at the beginning of this week."
And it's where she's a cut above the rest of the golfing world.
Ko defies her birth certificate.
She has hands of a golfing surgeon and the mind of canny veteran.
Several times during her round she was placed under extreme pressure from Yang and a host of chasers.
Yet each time she responded with aplomb in holding off Yang, Ariya Jutanugarn, while Perth's Minjee Lee fired a 72 to finish at -1 and top Australian, tied seventh.
Ko began shakily, uncharacteristically so.
She made a bogey at the first after coming up short at the par-four, then three-putted the par-five second for a par after hitting the green in two.
All that changed on the third, a driveable par-four in the classic Royal Melbourne mould, when she chipped in for eagle to regain the outright lead.
But she was on the rollercoaster, at least by her amazingly steady standards. At the short par-four eighth, her wedge shot hammered through the green and down into a deep swale behind the putting surface with virtually no chance of getting up and down.
The Kiwi tried a flop shot but it came back to her, and acknowledged her mistake later. A more conservative bump-and-run shot up the bank left her with a curling 3m putt for a bogey. She made it, which tells you a lot about her mentality.
"After I hit the shot, I said, "˜I should have just hit that (second) shot the first time'," she said.
"Even if I didn't make a par, it's an easier bogey and I had to work really hard for that bogey.
"I think that bogey putt was really good and if I'd made a double, today could have been a whole different story."
At that point she had lost the lead to Amy Yang, but her back nine was virtually flawless. She chipped up close at the par-five 10th to make a birdie, then she cut the corner at the dogleg 12th hole, hit it to 4m and her birdie putt trickled over the front edge. Back in front, she would not relent from there.
She closed with five consecutive pars, although she had one last flourish to deliver for the crowd. At the long, par-four 18th, she chose to drive down the first fairway -- a relatively common ploy over the years -- to open up the angle to the green, then hit a gorgeous short iron shot that almost hit the flag.
Anti-climactically, she missed the putt for birdie. But the tap-in par was enough for a 71 and a two-shot victory.
It was only three short years ago that Ko made world headlines by becoming the youngest ever winner of a professional tournament at the 2012 Women's New South Wales Open.
But she said much had changed despite being back on ground on which she felt was one of her "homes".
"It feels like a lot of things have happened in that time," Ko said.
"Not the time that I won, but the year before (2011) when I came second, it really helped me with my confidence.
"Just to know that I can be close in these professional events was such a cool thing that I realised and it gave me a lot of confidence and helped start my way towards becoming a professional "“ and it feels like a long time.
"I feel like I really want to go back to Oatlands again and play. It's a lot of great memories and a lot of things have happened in those years.
"Time flies, (but) I'm still 17 though."
Heaven help those who don't beat her soon.
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