Joe Ogilvie and Sergio Garcia share the lead at 3 under par. Ogilvie, who was eliminated on the first playoff hole last week at the Honda Classic, is through 13 holes, while Garcia completed six.
Tiger Woods, who won this tournament four years in a row from 2000-2003, is 2 under par through seven holes. He is currently the No. 1 ranked player in the world, but that title could be lost by Sunday.
Both Vijay Singh, who was No. 1 for 26 weeks before Woods reclaimed the post at the Ford Championship at Doral, and Ernie Els, who won back-to-back events on the European Tour, have a shot at the top spot.
Woods must finish outside the top two and Singh must finish no lower than tied fourth with one player. Els, who was No. 1 in the world for nine weeks, has a tougher road to the top of the perch. He must finish at least tied for second with one player.
Singh has not teed off in the first round and Els, who is playing with Woods and fifth-ranked Retief Goosen, is 1 over par through seven holes.
Kenny Perry joined Woods in a tie for third place at 2 under par and is through eight holes. K.J. Choi is at the same score through seven and Graeme McDowell is 2 under after five holes.
Mike Weir, Darren Clarke and reigning British Open champion Todd Hamilton are part of a group tied for seventh place at 1 under par.
Defending champion Chad Campbell is 1 over par and finished his opening nine.