Hunter Mahan denied Sweden’s Carl Pettersson and South African Louis Oosthuizen to claim victory in the Shell Houston Open.
Mahan is set to head into next week's Masters Tournament as the highest-ranked American after he claimed a single stroke victory in Texas.
Mahan held his nerve on the difficult 18th to claim a par and hold off Pettersson, who saw a birdie putt on the same hole fall narrowly short.
On a day when low scoring came at a premium Mahan's one under 71 was enough as playing partner and overnight leader Oosthuizen's challenge fell short with a three over 75.
Mahan's success moved him to the top of the FedEx Cup standings while the 29 year old is projected to move up to fourth in the Official World Golf Ranking ahead of the first Major of the year at Augusta National.
Three-time Major Champion Ernie Els finished ten under and fell short in his bid to earn an automatic invitation to this week's Masters.
Els needed a victory to avoid missing Augusta for the first time since 1993.
The problems for Oosthuizen began with a three-putt at the second. He holed a downhill 45 footer for a birdie on the third, but hit his tee shot at the fifth ended up in a divot and he subsequently missed the green with his approach. He botched a chip and two-putted from 20 feet.
Oosthuizen pulled his approach to the par five eighth, leading to his second double bogey, and there was to be no way back from an outward 41.