Starting the day with a four-stroke lead over YE Yang, Fowler carded a three-under-par effort to finish 16 under as not even consecutive bogeys on the last two holes at Woo Jeong Hills Country Club could derail his title charge.
"It was a lot of fun. I played well early on in the final round and then I was comfortable over the last few holes. Overall, I enjoyed the whole week," he told OneAsia's official website.
"It feels great to have the first win. I played well all week, although I did have to hang in on Friday and post a score. But on Thursday, Saturday and Sunday I had good control of my ball, I drove well, and I made some putts.
"I'm happy with the way I have played on the PGA Tour, but I have never shot low enough to win. This week I played well for four rounds which I have not been able to do that in the past.
"I will play mainly on the PGA Tour next year and I would like to get my first win there, and this win will defiantly help me achieve that. I also haven't made the Tour Championship in the last two years, so that is another goal for next year. But the biggest goal is to make sure I make the Ryder Cup team."
McIlroy, meanwhile, closed with a fine 64 to finish 10 under, but the Northern Irishman was undone by yesterday's 73 that left him 10 shots behind Fowler at the start of the day.
"It was a nice way to finish, but all the damage was done during the third round with a couple of bad holes in the middle of the round," he said.
"Looking back on this week, I will rue my third round, which could have been a lot better. If I had played a little better and shot a few under I might have had a chance, but Rickie has played fantastic this week and he deserves the win."
Korean Kim Meen-whee posted a level-par 71 to take third on seven under but Yang endured a disappointing final round as a 75 saw the veteran slip to fourth on five under par.