Five-shots ahead overnight, the South African more than doubled his winning margin with a blistering final round 65 on Sunday, leaving him seven under par for the day and 25-under overall. He dropped only a single shot all week.
In a display of precision putting, he hit eight final round birdies as he avenged last year's defeat to Lee Westwood and smashed the Englishman's tournament record score by three shots with a total of 263.
US Masters champion Bubba Watson finished strongly with 14-under overall, putting him tied second with 20-year-old Thai sensation Thitiphun Chuayprakong, while Ryder Cup star Sergio Garcia was two shots back in fourth.
It was Schwartzel's first win since claiming the 2011 US Masters, with the South African enduring a frustrating time since then due to injuries and poor form.
"It's been a good week. I've come close a few times but winning is not as easy as everyone makes it out to be," a beaming Schwartzel said of his ninth professional title.
"It's been a difficult year especially in the middle, it's nice to put things in place and get the win I've been looking for for a while."Making one bogey all week pretty much sums up how I played. I played pretty flawless golf. That's my personal best."
Schwartzel made a high-class field look ordinary as he breezed to the title, his 11-under the third-biggest winning margin ever recorded on the Asian Tour.
A birdie at the first banished any thoughts of a final day wobble. It was his nearest rival, Sweden's Daniel Chopra, who quickly felt the nerves, bogeying the first as he wilted in the Chonburi heat.
After seven dropped shots in a horror front nine, Chopra finished at 10-under, joining a clutch of players including Simon Dyson of England who finished a shot ahead of compatriot and world No. 6 Lee Westwood.
Home favourite Thitiphun led the chasing pack for much of the day hitting three birdies and delighting the crowd with a stunning eagle out off the bunker on the 11th.
"I'm so proud of how I played because I played with one of the best players in the world," the affable Thitiphun said, after claiming his near $85 000 prize for coming joint second. "The way he [Schwartzel] handled himself was fantastic. This is something I'm working on … we are getting there."
Watson posted a flawless seven under 65 for the last round, but he conceded his late charge was doomed to failure after a patchy first three days against the red-hot South African.
"Schwartzel played pretty good and my best stuff probably wouldn't have been as good," he said, adding error-strewn Friday and Saturday rounds stymied a genuine title challenge. – AFP