The former world number one shot a final round 70 to finish at 13-under-par at the Bay Hill course in Orlando, Florida, where has won six times before.
The American claimed his 72nd US PGA Tour title and his first since the BMW Championship in September 2009.
"It does feel good. It feels really good. It has been a lot of hard work," Woods said.
"I am so thankful for a lot of people helping me along the way, they know who they are."
Northern Ireland's Graeme McDowell, the 2010 US Open champion, finished second, five shots behind Woods, after starting the final round a shot in arrears.
The win was the first for Woods since the very public breakdown of his marriage after sordid details of his affairs were revealed.
It was also the first victory for Woods since the rebuilding of his swing by coach Sean Foley and comes just two weeks after he limped out of a US PGA Tour event at Doral, raising doubts about his fitness for the Masters.
McDowell was never able to mount a serious challenge to Woods after he made a double bogey on the first hole, going from one greenside bunker to another and closed with a 74.
"I believed I had a chance but I just never really got close enough to the guy," said McDowell.
"He played well and deserves his win and it is great to have him back winning tournaments. I think he is great for the world of golf and the excitement levels, atmosphere, television and fans, just great for this game," he added.
Woods led by four at the turn and maintained his composure on the back nine in a time to end his title drought and boost his confidence ahead of the Masters.
"This is a steady progression, this was coming. I've been close a number of times and just had to stay the course," said Woods.
Fast greens and high winds made for some challenging conditions but Woods limited himself to two bogeys and made some key saves, including a 13-foot putt for par on the 15th that gave Woods a four shot lead and effectively ended McDowell's hopes.
"That was an important putt," said Woods. "Three shots (is) easy to make up but four is a little bit different," he said.
"That was an important putt because, a three shot lead on the last three holes, if he makes eagle and I, says soup it on 16 or 18....three shots easy to make up but four is a little bit different...pretty comforting," he said.
Fans followed Woods down to the 18th green, cheering wildly and after he made par on the final hole, the old chant of "Tiger, Tiger" boomed out from the gallery.
"It was incredible to have that type of support here," said Woods.
"I used to live here for a long time, it was neat to see some of my friends come out and follow and it was just great atmosphere around all week."
Woods has already 14 majors but none since the 2008 U.S. Open and will be among the favourites to challenge at Augusta, along with the world's top two Luke Donald and Rory McIlroy.
"I'm excited there is no doubt. I am looking forward for the momentum that I've built here and the things that I have worked on in my game all coming together at the right time," he said.