Lam birdied three of the final four holes to finish with a 4-under 67 and the clubhouse lead over Australias Marcus Both (68) in a round delayed by lightning. Play was halted because of darkness with almost half the field unable to finish the opening round.
South Africas Ernie Els, who lost this tournament in a playoff in 2006 before missing the cut last year, was three under after 14 holes when play was called off, leaving him tied for second on the leaderboard with Englands Oliver Wilson and Indias Digvijay Singh.
Phil Mickelson, who lost his world number two ranking to Spains Sergio Garcia last week, shot a 2-over 73 and is six strokes off the pace in the $5 million event.
Irelands Padraig Harrington, winner of two majors in 2008, shot a 1-over 72, while two-time winner Adam Scott of Australia struggled with a 5-over 76.