Jaidee was joined in the lead after the first round by Ter-Chang Wang, Simon Dyson and David Higgins.
Andrew Buckle, Steven Jeppesen, Anthony Kang and Brad Kennedy each posted rounds of 5-under-par 67 and are one stroke back. Four more players are two strokes behind the leaders.
Jaidee jumped out of the gate with an eagle on the par-5 opening hole. He moved to 3-under with a birdie on the par-3 fourth at Emeralda Golf & Country Club.
The 36-year-old faltered to a bogey on the sixth, but got that stroke right back with a birdie on No. 7. Jaidee made the turn at minus-4 thanks to a birdie on the ninth.
Jaidee moved into the lead as he ran off three birdies in a four-hole span from the 11th. That run got him to 7-under. He parred his next three holes heading to the 18th. Jaidee stumbled to a bogey at the par-4 closing hole to slip back into a share of the lead.
Higgins birdied three of his first four holes to get off to a fast start. He then wrapped birdies at the sixth and eighth around a bogey on seven.
Around the turn, the Irishman got to 5-under with a birdie on No. 10. Higgins birdied the 12th to move into a share of first, but settled for six consecutive pars from there.
Wang, the only of the four leaders to start on the back nine, birdied the 10th. He carded his second birdie on the 12th, his third. Wang gave a stroke back to par on the 15th, but atoned for that error with a birdie on 17.
The Thailand native birdied the first three holes around the turn to jump to 5-under. Wang parred three straight before a birdie on the seventh got him to 6-under. He also birdied the eighth, but tripped to a bogey on No. 9, his last, to drop back to 6-under.
'I'm happy with how I performed today. This is my first time playing at this course and the experience has been enjoyable so far,' Wang said. 'I had a rather good spell on the front nine where I struck birdies on the first, second, third and eighth holes. I only missed the fairway once which was on the ninth hole.'
Dyson, like Jaidee, opened with an eagle on the first. The Englishman parred his next five holes before sinking his first birdie on the seventh. The streaky Dyson parred his next four holes.
The 28-year-old birdied the par-5 12th. Dyson made it two in a row as his birdie effort on the par-3 13th found the bottom of the cup. He birdied the 15th to get to minus-6, then parred his final three holes to close the only bogey-free round among the four leaders.
Thammanoon Srirot posted a 4-under-par 68. He was joined in a tie for ninth place by Wen-Chong Liang, Unho Park and Wilhelm Schauman. Damien McGrane, Stephen Dodd and Anders Hansen are among 10 players just one stroke further back at minus-3.