THOUSAND OAKS, California, Dec 2, 2012 (AFP) - McDowell, who capped a stellar 2010 season that saw him win the US Open with a victory in this unofficial post-season invitational, hadn't won anywhere in the world since then.
He carded a four-under par 68 on the soggy Sherwood Country Club course for a 72-hole total of 17-under 271 and a three-stroke victory over Keegan Bradley.
Bradley, the 2011 PGA Championship winner who started the day two shots off McDowell's lead, posted a 69 for 274.
"Just over the moon to get the job done," said McDowell, who took the lead in the second round on Friday and held on.
The 18-man event offers world ranking points and while it isn't part of any tour McDowell said the win added a nice flavor to a sometimes frustrating season that included a tie for second at the US Open, and a tie for fifth at the British Open.
"Certainly I will draw some confidence from this one," McDowell said. "The game hasn't given me a huge amount this year."
Bo Van Pelt carded a 70 for sole possession of third place on 278, while tournament host Woods carded a one-under 71 on the rain-soaked Sherwood Country Club course for a share of fourth place on 279.
Woods, who was joined by Jim Furyk (70) and Rickie Fowler (69), finished with two bogeys, a birdie and an eagle.
"Overall, I struggled with my game a little bit this week. I didn't quite have it," said Woods, who added that five days of rain left the course playing long and tough.
"I think it's hard to hit the ball close, just because the greens were so soft," he said. "Yesterday and today it played really long."
McDowell held a four-shot lead over playing partner Bradley through 12 holes, but things changed quickly at 13 thanks to his three-putt bogey and a birdie by Bradley.
"All of a sudden, it's 'Game on,'" said McDowell, who promptly pulled his driver into the trees at 14.
From 75 feet away he putted up to within a foot and made that to save par and preserve a two-stroke lead.
"Great two-putt there," he said. "And I made some solid swings coming down the stretch."
Bradley said that every time he thought he was closing in, McDowell produced the shots he needed.
"He played solid all day," Bradley said. "Just when I thought maybe I'd have a good chance, he'd hole a putt or hit a chip like he did on 17.
"You know, he's a champion, so I don't expect anything less out of him."
McDowell said his chip on 17, from rough above the green, was another key shot.
With Bradley on the green at the par-three, McDowell saw his chip slow when it hit the wet fringe, but then roll down toward the hole and leave him a tap-in for par.
"It nearly stuck in the fringe," McDowell said. "It was one one of those heart in the mouth things for a millisecond."
McDowell is planning a 10-week break before launching his 2013 campaign. He'll enjoy his time off in Northern Ireland and at his US home in Florida all the more now.
"It's been a hell of a two years since I sat here as a winner," he said. "We like to say that it's all about the processes and going through the motions and trying to get better. But let's be honest, we all measure ourselves by the wins."
Final-round scores on Sunday in the $4 million World Challenge golf tournament (USA unless noted, par-72):
271 - Graeme McDowell (NIR) 69-66-68-68
274 - Keegan Bradley 69-69-67-69
278 - Bo Van Pelt 70-68-70-70
279 - Jim Furyk 69-69-71-70, Rickie Fowler 73-67-70-69, Tiger Woods 70-69-69-71
281 - Webb Simpson 70-73-69-69
282 - Steve Stricker 73-71-68-70
283 - Hunter Mahan 71-73-71-68, Bubba Watson 71-74-67-71
284 - Matt Kuchar 73-69-72-70, Nick Watney 67-73-71-73
285 - Brandt Snedeker 75-68-73-69, Dustin Johnson 74-68-72-71
287 - Jason Dufner 73-68-75-71, Jason Day (AUS) 71-75-72-69
288 - Ian Poulter (ENG) 73-72-71-72
293 - Zach Johnson 74-70-70-79