Jaidee, 34, shot a 70 in the final round for a total of 21-under-par 267.
Randawa shot a 67 for 270.
Jaidee led the tournament, which is sanctioned by the European and Asian tours, from start to finish.
"This feels fantastic," Jaidee said. "This win is better than last year. I just told myself to play my own game. The driver didn't work well for me today, but the irons worked nicely."