"The challenge of that was to judge the speed where half the putt is through fringe and half is on the green," Mickelson said. "I got lucky to have made it, obviously. I was just trying to two-putt it. It was going fairly quickly when it got to the hole, probably would have been 6, 8 feet by. With Brandt in there close, that was a big momentum change."
Snedeker joked with Mickelson for a moment before holing his own birdie putt.
"Are you kidding me?" Snedeker said about his reaction to the putt. "I fully expected Phil to hit a flop shot from there. He didn't have much of a putt, and he putted through it.
"I hit a great shot in there close and I thought, 'Hey, I can get one on him here and put some pressure on him.' He makes that, and he let me hear about it before I putt, and he let me know that I needed to make that to tie. We had fun with it. That's Phil being Phil."
Mickelson shot a 4-under 67 to finish at 28-under 256, two strokes off the PGA Tour record of 254 set by Tommy Armour III in the 2003 Texas Open. The 42-year-old former Arizona State star won after struggling the last two weeks tying for 37th at La Quinta in his opener and 51st at Torrey Pines and making news by talking about tax increases.
"It's an important one for me, because it's been a while since I won, been a while since I've been in contention," Mickelson said. "I was certainly nervous heading into today. I think the thing I'm most excited about was the way I was able to regain control of my thoughts after a few shots early on that I didn't care for."
Mickelson missed a chance for a 59 in the first round when his birdie putt on the final hole caught the right edge of the cup, curled 180 degrees and stayed out. He settled for a 60 and followed with rounds of 65 and 64 to take a six-stroke lead into the final round.
"I think that sets up the tone for the rest of the year, because I really started to play well," Mickelson said. "But for me, the rest of the year took a turn on Tuesday when I got my new driver. It just changed my whole deal."
Snedeker finished second, four strokes back after a 65.
"Sometimes you have to tip your hat and say, 'Phil played unbelievable and deserved to win,'" Snedeker said. "That's kind of what this week was all about."
Phil Mickelson -28
Brandt Snedeker -24
Scott Piercy -23
Ryan Moore -22
Ryan Palmer -19