Yang who led 1 up through the opening 18 holes, was never down at any point in the match although it remained in the balance until a birdie at the 32nd hole gave him a two hole cushion which he was able to maintain.
Yang, a student at the University of San Diego, is just the second Korean after Byeong-Hun An won in 2009 to claim the amateur game's greatest title.
Danny Lee, who was born in Korea but spent much of his life in New Zealand, also won in 2008.
Yang has overcome back issues to rebuild his career but has had his scholarship at San Diego State taken from him of late through indifferent results. This win should go a long way to getting it back.
Yang is likely to be seen in Australia later this year when he plays the Asia Pacific Amateur Championship at Royal Melbourne in October.
He does have some background of playing golf in Australia while playing pennant golf in Melbourne before heading to the US.
No Australian made it to the 64 players who advanced to match play this week, West Australian Curtis Luck eliminated in a playoff for one of the places in that field