Choi, who finished at 17-under 271 through the 72-hole tourney, won the event with a 5-foot par putt at the 18th hole. He found the fairway off the 18th tee, but landed in a front greenside bunker before his winning putt.
The putt prevented a winner-take-all playoff, giving Choi his fifth victory on the PGA Tour and first since the 2006 Chrysler Championship.
"I like the fact that I put up a number that made (Choi) have to think about it coming down the stretch," said Moore. "Obviously, he performed and he made the putt he had to make."
Third-round leader Rod Pampling (72) and Kenny Perry (63) tied for third at 15-under 273.