McIlroy seized the 16th hole and belonged to two shots of the leaderboard LeadGenesis Open Final (US unless otherwise stated) -14: JB Holmes; -13: J Thomas; -12: S Kim (S Kor); -11: R McIlroy (NI), M Leishman (Aus) Other selected: -6: T Woods; -5: P Casey (Eng); -4: T Fleetwood; -3: D Willett (Eng); -2: S Garcia (Spa)
Rory McIlroy ensured a third consecutive top prize in a PGA Tour event when JB Holmes won the Genesis Open.
McIlroy, 29, started his last round with an eagle and moved only two shots of the lead after overtaking a bunker on the 16th.
But a par and a bogey left him fourth when Holmes closed the event in California.
The American, 36, threw back a 4-shot deficit in the last 18 holes when Justin Thomas won a four-over par-round and a single shot failed.
Just like McIlroy, 14-times-big winner Tiger Woods also chipped a greenside bunker on the 16th hole during a one-on-par round, finishing fifteenth on six-under overall.
Were Holmes slowplay accusations justified?
Holmes had not won on Tour since he claimed the Shell Houston Open in April 2015
It was Holmes' first win on Tour since 2015 and had a lot to thank him who had to deal with the windy conditions and disturbances due to bad weather at the course Riviera Country Club.
Both Holmes and compatriot Thomas played 33 holes on the last day due to suspensions earlier in the week playing, with only 30 minutes separating the end of their third round with the start of their last 18 holes.
And Holmes – who finished 14-under-par thanks to a one-under final round – found keyputts, especially on the 13th when he emptied a 12-foot par-putt, while Thomas needed four putts to finish a Double-bogey to close.
"Two three-putts and a four-putt on my back nine," Thomas said after drawing for a four-over-75. "The third pit at 13, I could feel the wind coming and I got scared, so I tried to hit him harder – and I hit it harder and that's why I missed it."
Holmes, who was seven pars made on his last seven holes, described his victory as "big" but got criticism from commentators and on social media for slowplay.
"You play wind in 25-mile-per-hour gusts and see how fast you play," he said afterwards. "You can not just go up and slap it when it blows so hard."
McIlroy's two-under-par final round of 69 saw him finish fourth with Australian rider Marc Leishman at 11 under.
An eagle in its opening hole caused an early impulse, but three falling shots on the back turned out to be nine precious.
The Northern Irishman finished in a draw for fifth place at both the Farmers Insurance Open on his last PGA Tour start and the Sentry Tournament of Champions in early January.