Plaphol played in one of the earliest groups off No. 1 and posted six birdies in a bogey-free round, finishing well before a downpour forced the suspension of play at 5:00 p.m. local time (5:00 a.m. ET) with 12 threesomes remaining on the course.
Finland's Mikko Ilonen was in second place at 5-under 66 after a round of seven birdies and two bogeys.
One shot further back, Shiv Kapur of India and Mad Vibe-Hastrup of Denmark shared third place in the clubhouse at 4-under 67. Korea's Jun-Won Park was 4 under par through 12 holes when the storm hit.
Plaphol, a winner on the Asian Tour last year, is seeking his first victory on the European Tour. This week's event at the par-71 Damai Indah Golf & Country Club is a co-sanctioned tournament.
'The key here is to keep it on the fairway because the wind tends to pick up in the afternoon so you have to strike it quite accurately off the tee,' Plaphol said.
The scores this week will be lower than they were last week at the Malaysian Open, where Peter Hedblom won with an 8-under 280 total.
'[But] the breeze means it will not get out of hand,' said Ilonen, who is also looking for his first European Tour win. 'If you get a still day here the course will offer you a lot of birdie chances.'
Defending champion Simon Dyson opened with two birdies in his first three holes, but went 1 over par the rest of the way and was tied for 25th place following a 70.
Fellow Englishman Philip Golding was only one shot further back at 71 despite opening his round with a quadruple-bogey at the par-5 first. He followed that by scoring a three on each of his next four holes and had five birdies on the day.