With a final round of 1-under 71, Hunter Mahan won the Shell Houston Open by a shot over Carl Pettersson.
Mahan is the first player to earn multiple PGA Tour wins this season.
Brian Davis and 54-hole leader Louis Oosthuizen finished in a tie for third at 13 under. Oosthuizen closed with 4-over 76.
Jeff Overton, Keegan Bradley, Phil Mickelson and James Driscoll tied for fifth, four back of the lead.
Ernie Els, who needed a win to get into the Masters for a 19th consecutive year, finished T-12 and a half-dozen shots back of Mahan.
Mahan becomes the No. 4 player the Official World Golf Ranking with the win, the highest ranked American heading to Augusta.