By Mark Lamport-Stokes
Crane overhauled third-round leader Ryuji Imada of Japan with three birdies in the first five holes and survived a nervy finish at Torrey Pines to card a two-under-par 70 for a 13-under total of 275.
The 33-year-old missed a three-footer to bogey the 17th but he parred the last on the brutal South Course to earn his first win on the U.S. circuit since the 2005 Milwaukee Championship.
"I was working so hard with my caddie coming down the last few holes just to not get involved in the score and outcome and all that," Crane told reporters after earning the winner's cheque for $954,000.
"It was a grind but I'm very thankful I came out on top. It's really cool to know I'm going in the right direction."
Australian Mark Leishman, the 2009 PGA Tour rookie of the year, birdied two of the last three holes for a 68 and a tie for second with compatriot Michael Sim (71) and American Brandt Snedeker (69).
The American world number two, making his first tournament appearance of the year, bogeyed the first three holes en route to a 73 and 19th place at eight under.
"I was really excited about playing, maybe I was a little over-anxious," Mickelson said. "I got off to a terrible start and throughout the round I didn't get much out of it."
Crane began another sun-kissed day on the California coastline two strokes behind the pacesetting Imada and he recorded his first birdie at the par-four second where he struck a superb approach to three feet.
Crane rolled in a 45-foot birdie putt up the hill while his Japanese playing partner bogeyed after three-putting from long range.
Two holes later, the American picked up his third shot, ramming in a 22-footer and pumping his right fist in celebration after the ball disappeared into the cup.
Out in a flawless three-under 33, Crane drained a 48-footer at the par-three 11th to keep his closest challengers at bay.
"I made two putts today that you certainly never expect to make," he said of his two birdies from more than 40 feet. "I was not trying to make those putts, I was just trying to put a good stroke on it, and they happened to go in."
Crane collected his first bogey of the round at the par-five 13th, where he three-putted from 14 feet, and also stumbled at the par-four 17th when he pushed his short par putt wide of the left edge of the cup.
Despite finding the right rough off the tee at the par-five last, Crane laid up in two on the way to a regulation five and a one-stroke victory.
Australian Robert Allenby made a strong bid for his fifth PGA Tour win with five birdies in the first 13 holes but he fell out of second place by losing five shots in four holes.
(Editing by John O'Brien)