Martin Laird tied the course record with a nine-under-par 63 to hold off Rory McIlory and earn his first win in more than two years at the Texas Open.
Laird began Sunday four shots behind leader Billy Horschel, but posted a bogey-free round to finish 14 under overall and earn the third win of his career, his first since the Arnold Palmer Invitational in 2011.
The Scottish golfer entered the week having missed four of eight cuts this year.
McIlroy, the world No.2, began the day at six under before posting a 66 to finish two shots back in second – his best finish of the year.
Horschel shot a 71 to finish in a tie for third with Jim Furyk and Charley Hoffman.
Aaron Baddeley closed with a 69 to finish as top Australian, equal 15th at four under for the championship.