The big-hitting Thai carded a third-round two-under-par 70 for a 54-hole total of 13-under 203, a shot ahead of Italy's Edoardo Molinari at the $2.75 million co-sanctioned Asian Tour event.
The 23-year-old topped the leaderboard on all four days at the Kuala Lumpur Golf and Country Club and could afford to bogey the par five 18th and still win the tournament despite his anxiety after another delay in play on Sunday.
"During the suspension, I couldn't eat anything. I was so excited. When I walked out, everything was shaking, even my voice," said the burly Kiradech, whose thyroid problem affected his stamina and prevented him from giving it his all on some drives.
"My caddie told me to just concentrate, 'just two more holes'. I'm lucky that I played only 54 holes. Otherwise, I am so tired due to the weather and the golf course.
"This means a lot to me. I have to thank my family... my mum and my dad for all their support."
Denmark's Anders Hansen finished third after a stellar six-under-par 66, the joint best round of the day, with South African Charl Schwartzel and France's Victor Dubuisson, a shot further back in fourth.
Ireland's triple Major winner Padraig Harrington and Pablo Larrazabal of Spain were among five players tied for sixth, four shots behind the winner.
Molinari, who has been bothered by a troublesome wrist issue which required surgery early last year, was pleased to card a bogey-free round of five-under 67 but was left thinking of missed opportunities.
"It's mixed emotions because I'm very happy to have a good week for the first time in a long time," he said. "The swing changes are starting to pay off which is surprising because I thought it would take a lot longer.
"I'm disappointed because I had a lot of chances on the back nine. The 18th is only the second fairway I missed all day which is very disappointing.
"I felt if I birdied the last I might have won outright because it puts a lot of pressure on the guy coming up behind."