SAN DIEGO: American Bubba Watson held off late charges by Phil Mickelson and Venezuela's Jhonattan Vegas to clinch his second PGA Tour title with an emotional one-shot victory at the Farmers Insurance Open Sunday. Left-hander Watson coolly birdied the par-five last to keep his challengers at bay as he closed with a sparkling five-under-par 67 on the tricky South Course at Torrey Pines. The long-hitting 32-year-old, a stroke off the pace going into the final round, got up and down from a greenside bunker at the 18th, sinking a curling 12-footer before pumping his right fist in celebration. Three-time champion Mickelson had a chance to force a playoff by holing a wedge shot from 72 yards out but his ball ended up four feet from the pin to set up a closing birdie. “It means a lot,” a tearful Watson, whose father Gerry died late last year after a lengthy battle with lung cancer, said greenside. “My dad is not here. Mom, I love you.” Asked if his breakthrough win at last year's Travelers Championship had helped him at Torrey Pines, Watson replied: “No. It's hard every time you look at it. “You've got Phil, you've got the guy who won last week, Vegas. All I thought about today was keeping my head down. And I did that.” San Diego native Mickelson closed with a 69 to secure second place while PGA Tour rookie Vegas, winner of last week's Bob Hope Classic, bogeyed the last for a 68 and a tie for third at 13 under with American Dustin Johnson (66). “I'm disappointed because I wanted to start the year off with a win,” said Mickelson. “But on the other hand, I played really good golf and gave myself an opportunity. “Bubba played some terrific golf. I did what I thought would be enough, and it just wasn't. Bubba played too good. He made great shot after great shot, and putt after putt.” Six-time winner Tiger Woods, playing his first event of the year, ended a frustrating week with an erratic three-over 75 to share 44th place, a distant 15 strokes off the pace. “I hit a lot of good shots early in the week, and then it progressively got worse,” said Woods. “I have some work to do. There's no doubt about that.” Mickelson attracted a huge gallery when he teed off with co-leader Bill Haas in cool, mainly overcast conditions and he briefly led by one after Haas bogeyed the opening hole. Watson drew level by knocking in a three-footer to birdie the par-three third and he, fellow left-hander Mickelson and Vegas then duelled for supremacy for the rest of the day. Vegas, with birdies at 12 and 13, and Mickelson, who horseshoed out with a 21-foot eagle putt on the 13th green, piled on the pressure but Watson stayed in front. He produced flawless golf over the back nine, got to 15 under with a two-putt birdie at the 13th and calmly sank a nine-footer to save par at the 17th. Mickelson recovered with a birdie at the 17th where he struck a wedge to three feet. The bold bid by Vegas to win consecutive titles on the US circuit effectively ended at the last when he hit his second shot into the pond guarding the front of the green.