Kim, who was co-leading going into the final round, fired a bogey-free 64 for his lowest round of the week in La Quinta, California. He trailed Cantlay by one with three to play and proceeded to birdie the par-5 16th before draining an 18-footer on No. 17 to move in front.
A par on his final hole secured the victory for his third on the PGA Tour and first since winning the 2017 Players Championship when he became the youngest winner at TPC Sawgrass at the age of 21.
Cantlay put relentless pressure on Kim all day. The world No. 10 shot a course-record 61 to hold the clubhouse lead at 22-under but ultimately wound up one stroke shy of a playoff.
Here's how the top of the leaderboard finished:
|Place||Player||To Par||R4 Score|
|1||Si Woo Kim||-23||64|
The PGA Tour heads to Torrey Pines next week for the Farmers Insurance Open.