(MENAFN - Kora)
The American's third PGA Tour win and second of 2014 was secured with a five-foot par putt at the 18th at Pebble Beach Golf Links in California, but not before a nervy finish, which saw Walker bogey four holes on the back nine to almost throw away victory.
Walker, 35, secured the title, despite pushing a birdie putt five feet beyond the hole at the 18th.
Dustin Johnson and Jim Renner were in the clubhouse a shot back at 10 under as Walker faltered late in his round, but no play-off was required.
Walker's two-over 74 at Pebble Beach the course hosting all players on Sunday was his worst round of the tournament.
Johnson (66) and Renner (67) surged up the leaderboard, while Jordan Spieth (67) recovered from his third-round 78 to finish tied for fourth.
Walker was six shots clear heading into the final round after strong winds troubled several players on Saturday.
His front nine was largely uneventful despite a bogey at the first, with birdies at the second and eighth holes keeping him in control.
But three bogeys in four holes starting at the 10th, along with a birdie at the 11th, suddenly put him under some pressure.
Walker three-putted from 27 feet for a bogey at the par-three 17th and looked in some trouble at the par-five 18th.
His drive went into the rough, as did his second shot, but his third was on the green, only to put too much pace on his first putt.
With Johnson and Renner looking set for an unlikely play-off spot, Walker regathered his composure to sink the five-footer for the victory.
Kevin Na (69) was alongside Spieth in fourth, a shot clear of Hunter Mahan, who ended up outright sixth.
Northern Irishman Graeme McDowell (67), New Zealander Tim Wilkinson (73) and American Pat Perez (71) were equal seventh at six under.