Choi converted a five-foot par putt on the 72nd hole to hold off Moore, and also escaped charges from Rod Pampling and Adam Scott. He will be back to defend his title against a field that includes 14 of the top-20 ranked players in the world.
Three-time Memorial champion Tiger Woods will be the most notable name not on the leaderboard as he continues to recover from the knee surgery he had two days after the Masters.
Woods won Jack Nicklaus' tournament three straight years from 1999-2001, and there hasn't been a repeat winner since then. Five of the last six champions -- Choi, Carl Pettersson, Bart Bryant, Kenny Perry and Jim Furyk -- will all be in the field this week.
The GOLF CHANNEL and CBS will split coverage this weekend.
Next week is the Stanford St. Jude Championship, where Woody Austin shot a 62 in the final round to win last year.