LOS ANGELES, February 17, 2014 (AFP) - After sweating out six straight pars to preserve his one-shot lead, Watson was surprised to see a 14-footer fall for a finishing flourish at Riviera Country Club.
His 15-under total of 269 gave him a two-stroke victory over eight-time US PGA Tour winner Dustin Johnson.
"It doesn't feel like two years," Watson said of his long wait to claim another title after making his major breakthrough at Augusta. "It's crazy that it's coming up on two years."
He was pleased to win on the classic Riviera course, where he had leapt into contention on Saturday with what proved to be just his first bogey-free seven-under 64 of the weekend.
Johnson also played without a bogey on Sunday, but his five-under par 66 was only good enough for second on 271.
"When you shoot 14-under on the weekend, it's tough to beat that," Johnson said.
Monday qualifier Jason Allred had three birdies in his three-under 68 for a share of third place on 272 alongside Brian Harman, who closed with a 68.
Another former Masters champion, South African Charl Schwartzel, was alone in fifth after a 68 for 273.
Schwartzel was one of the four players who shared the lead early in the round before Watson got his nose in front in his race for a fifth US PGA Tour title.
Watson birdied five of his first eight holes.
That included holing out from a greenside bunker at the par-three sixth. Watson admitted that owed something to luck, but still added to his momentum.
"Basically when I was going in there I was thinking at worst let's make a four and get out of here (or) give ourselves a chance for a 10-footer for par," Watson said. "Then when it goes in ... I knew that pushed me close to the lead."
Watson rolled in a 16-foot birdie putt to take a one-shot lead at the eighth, and stretched his lead to two strokes with a birdie at the par-five 11th.
Johnson and Schwartzel tried to keep the pressure on.
Johnson birdied the 15th to trim the lead to one, but he couldn't take advantage of the par-five 17th and was in the clubhouse one stroke off Watson's lead.
Schwartzel bounced back from a bogey at the 13th by holing out from a bunker for a birdie at the par-three 14th, but a bogey at 15 effectively ended his challenge.
Overnight leader William McGirt's bid for a first US PGA title got off to a promising start with a birdie at the first, but he was unable to find another and finished with a two-over 73 that dropped him into a four-way tie for sixth on 10-under par alongside fellow Americans Bryce Molder, Matt Every and George McNeill.
Watson had shown signs this season that he could soon be headed to the winner's circle.
He took a two-stroke lead into the final round of the Phoenix Open a fortnight ago, settling for a share of second behind Kevin Stadler after missing a five-footer to save par at the 72nd hole and force a playoff.
Even as his winless run stretched on, Watson said he never felt discouraged.
"I never looked down, I never felt down that I haven't won yet, but just kept plugging away and somehow it fell in my lap today," he said.
Leading final scores on Sunday in the US PGA Tour $6.7 million Northern Trust Open (USA unless noted, par-71):
269 - Bubba Watson 70-71-64-64
271 - Dustin Johnson 66-70-69-66
272 - Brian Harman 67-69-68-68, Jason Allred 73-64-67-68
273 - Charl Schwartzel (RSA) 69-68-68-68
274 - Bryce Molder 69-69-69-67, Matt Every 69-69-69-67, William McGirt 69-67-65-73, George McNeill 69-68-66-71
275 - Harris English 70-69-69-67, Brendan Steele 68-71-67-69
276 - KJ Choi (KOR) 69-72-67-68, Charley Hoffman 67-71-68-70, Bae Sang-Moon (KOR) 67-66-72-71, Cameron Tringale 68-70-67-71, Jordan Spieth 72-66-67-71, Charlie Beljan 67-68-68-73
277 - Aaron Baddeley (AUS) 69-65-72-71, John Senden (AUS) 71-70-66-70
278 - Keegan Bradley 68-70-72-68, Lee Westwood (ENG) 69-70-68-71, Jimmy Walker 67-71-67-73
279 - Kevin Chappell 71-70-69-69, Kevin Stadler 69-69-74-67, Jim Furyk 68-68-71-72, Robert Garrigus 67-67-73-72, Hideki Matsuyama (JPN) 70-69-69-71, Bill Haas 72-67-67-73