PEBBLE BEACH, February 10, 2014 (AFP) - Walker carded a two-over par 74 in the final round for an 11-under par total of 276, rolling in a five-footer for par at the 72nd hole to claim the trophy.
Two-time Pebble Beach Pro-Am winner Dustin Johnson and Jim Renner tied for second at 277, Johnson climbing up the leaderboard with a 66 and Renner carding a 77.
Walker had held a six-shot lead when the third round in the weather-disrupted tournament was wrapped up on Sunday morning.
Walker had come from behind in his prior two victories this season -- the Frys.com Open in October which was the first event of the US tour's "wrap-around" 2013-14 season and the Sony Open in January.
He acknowledged that he felt the pressure of trying to hold on to a big lead.
"You could tell that with the little wedge shot up the hill, then the three-putt (on 17)," Walker said, describing the last of his five bogeys.
"I got little off edge. I was still hitting it pretty good, but lost some touch stuff. It was nice to make that last one."
Jordan Spieth carded a 67 and Kevin Na a 68 to share fourth place on eight-under 279.
Hunter Mahan posted an even-par 72 for solo sixth place on 280.
Northern Ireland's Graeme McDowell, playing at Pebble Beach for the first time since he won the 2010 US Open on the iconic course overlooking the Pacific Ocean, closed with a 67 for 281. he was joined in seventh place by Pat Perez (71) and New Zealand's Tim Wilkinson (73).
Walker's six-stroke third-round lead dropped to five strokes when he was unable to get up and down for par from a greenside bunker at the first hole.
Birdies at the second and eighth let him rebuild his cushion, but he was clearly feeling the pressure of being expected to win on the back nine.
Walker bogeyed the 10th from a bunker, but responded with a 10-foot birdie at 11.
He missed the green at the par-three 12th en route to a bogey, and after a three-putt bogey at 13 his lead was down to three strokes.
His three-putt bogey at 17 -- after Johnson and Renner both birdied 18 -- sent him to the final tee with a one-shot lead, and he promptly fired his tee shot into the right rough.
His attempt to lay up was also in the rough and from there he left himself more than 20 feet to the pin. He ran his birdie attempt five feet past, but made the par putt coming back.
"It is a different feeling when you have a big lead. I know pars are going to be good enough," Walker said. "I struggled a little bit with the speed of some of the greens and my chipping. I made a really good putt at the last."
Leading final-round scores on Sunday in the $6.6 million Pebble Beach National Pro-Am on the par-72 Pebble Beach Golf Links, par-71 Monterey Peninsula, par-72 Spyglass Hill (USA unless noted):
276 - Jimmy Walker 66-69-67-74
277 - Dustin Johnson 68-73-70-66, Jim Renner 65-73-72-67
279 - Jordan Spieth 67-67-78-67, Kevin Na 72-68-70-69
280 - Hunter Mahan 68-68-72-72
281 - Graeme McDowell (NIR) 71-71-72-67, Pat Perez 69-70-71-71, Tim Wilkinson (NZL) 67-72-69-73
282 - Bryce Molder 72-71-69-70, Chesson Hadley 71-70-70-71, Richard H. Lee 65-72-72-73
283 - Will MacKenzie 69-74-70-70, Cameron Tringale 70-73-71-69, Patrick Reed 69-70-75-69, Victor Dubuisson (FRA) 73-67-74-69, Brian Davis (ENG) 68-74-70-71, Scott Gardiner (AUS) 65-73-77-68
284 - Steven Bowditch (AUS) 68-70-75-71, Noh Seung-Yul (KOR) 72-71-71-70, Daniel Summerhays 69-69-74-72, Jason Kokrak 74-68-70-72, Brice Garnett 75-68-68-73, Roberto Castro 70-73-71-70, Michael Thompson 71-68-72-73, Phil Mickelson 66-73-71-74
285 - Padraig Harrington (IRL) 72-69-72-72, Andrew Loupe 63-73-76-73, Russell Knox (SCO) 70-72-70-73, Jim Herman 70-70-71-74, Robert Garrigus 67-71-73-74