Interestingly the last New Zealand victory also came in Adelaide although at the nearby Royal Adelaide Golf Club.
Koh, from Auckland's Manukau Golf Club, went one up at the very first hole this morning and was never headed as he led by four through nine holes, four through the first eighteen and eventually won at the 31st hole by the margin of 6&5.
The 19 year old has made it to the semi finals of the New Zealand Amateur over the past two years but a victory over local Anthony Murdaca in yesterday's semi final got him through to his match against Luck today. Koh had beaten American Max Buckley in Saturday morning's quarter final.
Born in Korea, Koh moved to New Zealand at the age of six and began playing golf when he was seven after caddying for this father. He stopped playing golf for four years in his early teens to pursue cricket and soccer before returning to the golf course four and half years ago.
The Australian Women's Amateur went to the defending champion Minjee Lee from the Royal Fremantle Golf Club south of Perth, who defeated 15 year old Gold Coaster, Karis Davidson, 6&5 after fighting back from an early deficit.
The 17 year old Lee whose titles include the 2012 US Girls Amateur, is now likely to move considerably higher than her current 5th place position in the World Amateur ranking and consolidates her position atop the Australian women's rankings.