Randhawa totalled nine-under 207 after striking five birdies against a three bogeys in a roller-coaster third round.
Another senior pro, Jeev Milkha Singh was three strokes behind Randhawa at tied 48th after carding a 69 in the third round.
Jeev mixed three birdies with a lone bogey for a reasonably good outing.
Further down, Delhi-golfer Shiv Kapur took the tied 57th position with a total of five-under 211 after turning in an even-par 72.
Kapur managed three birdies but was pulled back by an equal number of bogeys.
Bradley Dredge (67) led the pack with a total of 18-under 198, followed by Simon Thornton (67) and Ross Fisher (66) both of whom totalled 15-under 201.