Couples shot a 6-under 65 in the fourth round to down Ronnie Black by four shots, less than a month after claiming the trophy in his last Champions Tour appearance in the ACE Group Classic.
He was the runner-up in his Champions Tour debut at Hualalai Jan. 24.
"You know, it looks easier than it really is," said Couples after collecting $255,000 for the win.
Black also shot a 65 Sunday to grab sole possession of second place, a distant four shots back at 14-under 199. Tom Lehman (69) and Chien Soon Lu (69) of Taiwan tied for third place at 12-under 201.
Tom Watson carded a 9-under 62 to finish in a fourth-place tie with Loren Roberts (68) at 202.
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