The field includes 33 players who received invitations by virtue of winning a European Tour event in 2012.
Jaidee had birdies at Nos. 2 and 3 and added another at the fifth hole. Birdies at 7 and 8 had him 5-under through eight holes. He had another birdie at No. 10 and got to 7-under the first time with a birdie at the 194-yard, par-3 15th.
He gave that stroke back with a bogey at 17 but posted a birdie at the 273-yard, par-4 closing hole.
Windy conditions affected play much of the day, as shown by Oosthuizen's up-and-down round of seven birdies and three bogeys. Els opened his round with three birdies but suffered a double bogey at the par-3 fifth. He had four birdies and one bogey the rest of the way.
'SNL': 'Anchorman 2' cast, One Direction sing 'Afternoon Delight' [VIDEO]
Ukrainian protestors topple Lenin statue [VIDEO]