The Weyburn, Saskatchewan native entered the day in sole possession of second place, two shots behind 54-hole leader Retief Goosen.
Goosen stumbled to a 4-over-par 75 and also fell back into 8th spot along with Sang Moon-Bae, who recorded a score of 72. The trio teed off together for the final round.
James Hahn won the tournament in a three-man playoff with a 25-foot birdie putt on the third extra hole for his first PGA Tour title and a trip to the Masters.
In a wild finish just as the Academy Awards was getting started, Hahn saved par on the 18th in regulation for a 2-under 69 that got him into a playoff with Dustin Johnson (69) and Paul Casey (68).
Casey was eliminated on the second extra hole — No. 10 — when Hahn and Johnson hit dangerous flop shots over the back bunker and converted birdie putts.
On the par-3 14th, Hahn made his birdie and then kept his head down as Johnson missed a 12-footer.