Gangjee opened with two bogeys, but recovered with three birdies in a row from fifth to seventh, only to give away his third bogey of the front nine on eighth. He birdied the 11th, bogeyed the 14th, birdied the 17th and gave away a shot on the last. He finished at four-under 280.
Daniel Chopra (69) was two-under 282 and finished tied 48th.
Meanwhile, Hudson Swafford, starting the day five off the lead, fired a nine-under 62 to rally to a fine win that sent home fans into great joy. He totalled 17-under 267 but then waited for more than an hour and a half to see if he had won.
He finished one better than Luke List winner of last week's South Georgia Classic and two-time US Open champion, Lee Janzen, who birdies seven of his last eight holes, including last five.
Billy Horschel (68) was fourth and Tyrone Van Aswegen (70) was fifth.
