Woods, playing with Mickelson in the penultimate pairing, shot a 4 under 67 while Oberholser had a final round 69.
Olberholser had a chance to finish alone in second place but missed a relatively short birdie putt on 18. Wetterich toured the course in the final round with a 1 under 70.
The win is Mickelson's 32nd on the PGA Tour. After winning Mickelson said he wasn't sure if he'd play in next week's event because of a dispute he has with PGA commissioner Tim Finchem.
(Copyright 2007 by The Associated Press. All Rights Reserved.)