Andrew Landry blew a six-shot lead before steadying to secure victory at The American Express in California.
Andrew Landry and countryman Scottie Scheffler are four strokes clear atop the leaderboard after Saturday's penultimate round.
Rickie Fowler continued his good form at The American Express, sharing the lead at the halfway mark.
A seven-under 65 left Rickie Fowler in a tie for third after The American Express first round.
American golfer Adam Long earned a one-stroke victory following his final-round 65 on Sunday.
Phil Mickelson carded a six-under-par 66 to stay two strokes clear at the PGA Tour tournament on Saturday.
Phil Mickelson, who posted a career-low 60 in round one, carded a four-under-par 68 at the at the Nicklaus Tournament Course on Friday.
Phil Mickelson opened up a three-shot lead at the Desert Classic thanks to a first-round 60.
After winning the CareerBuilder Challenge, Jon Rahm is set to climb into second in the world rankings.
Spaniard Jon Rahm claimed the CareerBuilder Challenge title after a play-off.