The 40-year-old reached 8- under and holds a one-shot lead on Lee Westwood (65) Stephen Dodd (69) and Miguel Angel Jimenez (67).
A double bogey at the last hole left first-round leader Rory McIlroy at 70, among a group of five players two shots behind.
Tom Watson also shot 70 to trail by five shots. Colin Montgomerie (76) fell 11 strokes back.
Jaidee has four career wins on the European Tour, including the Indonesia Open and the Ballantine’s Championship in 2009.
He sees this event as a warmup for the Masters Tournament. In 2006, Jaidee missed the cut at Augusta after shooting 78 and 75. After overcoming a serious back injury sustained two years ago, he wants a second chance at the Masters.
“When I went to Augusta (the) first time, I was not familiar with the place,” he said. “I didn’t know those greens. I three-putted seven times and had one four-putt. I would like to get that right.
“I am driving the ball well, hitting my irons well and having worked hard on my putting. That’s what I need here and for the Masters.”
NATIONWIDE TOUR: In Fingal, Australia, Jim Herman shot 2-under-par 70 to take a three-stroke lead after the second round of the Moonah Classic.
Herman, who shot a course-record 62 at Moonah Links on Thursday, had a bogey-free, two-round total of 12-under 132 on the course designed by five-time British Open champion Peter Thomson.
Aiken’s Stephen Poole (72) is at 142, while North Augusta’s Scott Brown (69) and Aiken’s Kevin Kisner (73) are at 145.
Asian tour International: In Bangkok, Thailand, Mars Pucay, of the Philippines, shot his second consecutive 69 and is tied for the lead in the Asian Tour event with Thailand’s Kiradech Aphibarnrat, who has shot 68-70.