Kruger was 2-over on the front nine of his second round but the run of birdies, in a seven-hole span, gave him a 4-under-par 66 that put him at 7-under 133.
Stuart Manley, despite three bogeys, turned in a 67 and is in second place at 6-under, one stroke back of Kruger. Shiv Kapur, who had four birdies over Nos. 13-17, shot 66 and is tied with Alex Cejka and Wade Ormsby for third at 5-under.
Eight players, including first-round co-leaders Andrew Dodt and Prom Meesawat, sit at 4-under.
Kruger opened his round with a bogey at the first hole. He pulled back to even with a third-hole birdie only to bogey No. 4, a 288-yard, par-4. A bogey at the 493-yard, par-4 ninth left him 2-over.
But he ran off four straight birdies beginning at the 11th hole and added two more at 16 and 17 to move into the lead. He had just six putts in the series of birdies, with four less than 10 feet.