The reigning Masters champion has been as high as No. 2 in the world, but hasn't finished a year higher than No. 18 since 2017.
The victory is the 29-year-old Matsuyama's eighth PGA Tour title, tying South Korea's K.J. Choi for the most wins by a player from Asia.
Henley's his 18-under par total of 192 was enough to stay in front of Matsuyama, who charged up the leaderboard with a seven-under par 63 that featured seven birdies.