Aiken opened the day four strokes behind the leaders but used eight birdies and a pitch-in eagle in moving to the top of the leaderboard at 18-under 198 after 54 holes.
Liang Wen-chong, who started the day in a tie for first, was 3-under 69, which included a pair of bogeys, and is in second. Kiradech Aphibarnrat shot 66 Saturday and David Drysdale had a third-round 68, leaving them tied for third at 14-under.
Three players are 13-under and Chapchai Nirat, who was tied with Liang after Friday's play, shot even-par 72 in sliding into a four-way tie for eighth at 12-under.
Aiken's iron play was strong Saturday. In addition to pitching in for eagle, he had five birdie putts of less and 10 feet.
He opened the day with a birdie and pitched in for eagle at the par-5 second. Three birdies over Nos. 5-8 allowed him to make the turn at 6-under.
He had back-to-back birdies twice in the second nine, first at 10 and 11 and again at Nos. 15 and 16.
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