Maggert shot a 5-under 65 Sunday to beat Tom Pernice, Jr. by two shots at 9-under 271.
The PGA TOUR's Memphis stop was pushed back two weeks this year in a schedule re-shuffle ahead of the U.S. Open. It may have taken a hit already after Phil Mickelson withdrew from last week's Memorial with a left wrist injury.
As of Monday, Mickelson's name was still listed in the field. But in a release posted on his Web site last Friday, he said his chances of playing this week were '50-50.'
Without Mickelson, the highest-ranked player in the field this week would be No. 4 Adam Scott, who was one of a handful of players edged by K.J. Choi at the Memorial on Sunday.
The GOLF CHANNEL will have live coverage and replays of the first two rounds, and CBS will broadcast the weekend action.
Next week is the season's second major, the U.S. Open at Oakmont. Geoff Ogilvy won last year's U.S. Open after Mickelson's now-infamous collapse on the 72nd hole at Winged Foot.