Ben Crane withstood a nervy finish to claim a one-shot victory at the Farmers Insurance Open at Torrey Pines in San Diego.

American Crane landed the third PGA Tour win of his career with a 13 under par total thanks to a closing two-under-par 70, having started the day two strokes behind 54-hole leader Ryuji Imada of Japan.

Having held a two-shot lead going to the 17th, Crane bogeyed the penultimate hole to narrow his advantage heading to the 72nd hole, with Australia's Michael Sim, playing alongside, Marc Leishman and American Brandt Snedeker in the clubhouse, all on 12 under.

Rookie Sim could not add further pressure on Crane as he parred the last for a 71 to stay at 12 under, leaving Crane to putt for par and victory.

American Michael Allen shot a seven-under-par 65 on his 51st birthday to claim a share of fifth place at 11 under alongside PGA Tour rookies Alex Prugh (66) and Rickie Fowler (70) and South Africa's Ernie Els (69).

Imada's hopes of a third victory of his own in the US faded early after he bogeyed two of his first seven holes and the Japanese player finished with a three over 75 at 10 under in a tie for ninth with 2009 champion Nick Watney, Charles Howell III and DA Points of the United States and Robert Allenby of Australia.

Fowler's hopes of a maiden victory had disappeared at the par-four 17th, where he double bogeyed on the way to a 70 while Allenby had also been in contention until he got the wrong end of a ruling having sent his ball into a hazard at the 17th.

No-one but Allenby saw the ball enter the hazard and, having been unable to find it, the official said its presence in a thicket could not be verified and therefore the Australian had to go back to the tee box rather than being allowed a drop.

The subsequent triple bogey followed bogeys at the 14th and 15th but Allenby finished in style with an eagle three at the last.

World number two Phil Mickelson struggled in his home town on the final day. The left-hander started four strokes behind Imada but was quickly on the back foot with three bogeys in a row to open and the American finished with a one-over 73 to close at eight under for the week.

Sweden's Fredrik Jacobson and Justin Rose of England each shot a closing 70 to close at six under in a tie for 22nd, while Scotsman Martin Laird saved his best round of the week for last with a 68 to get to five under and a tie for 27th.

Englishman Luke Donald finished with a 73 following rounds of 70, 72 and 72 to drop to one under for the week.

Collated final-round scores & totals (USA unless stated, par 72):

Torrey Pines (South Course)

275 Ben Crane 65 71 69 70

276 Michael Sim (Aus) 73 62 70 71, Marc Leishman (Aus) 68 69 71 68, Brandt Snedeker 71 68 68 69

277 Michael Allen 72 66 74 65, Ernie Els (Rsa) 70 69 69 69, Rickie Fowler 67 70 70 70, Alex Prugh 67 71 73 66

278 D.A. Points 68 65 74 71, Nick Watney 71 70 69 68, Robert Allenby (Aus) 67 69 72 70, Lucas Glover 71 67 68 72, Ryuji Imada (Jpn) 65 68 70 75, Charles Howell III 71 69 70 68

279 K J Choi (Kor) 72 66 69 72, Matthew Every 65 70 72 72, Kevin Sutherland 74 67 70 68, Troy Merritt 69 72 67 71

280 Phil Mickelson 70 67 70 73

281 John Rollins 70 66 74 71, Scott Piercy 64 75 73 69

282 Ricky Barnes 67 75 72 68, Spencer Levin 69 70 70 73, Justin Rose (Eng) 71 69 72 70, Fredrik Jacobson (Swe) 71 69 72 70, Vance Veazey 67 71 71 73

283 David Lutterus (Rsa) 69 70 74 70, Hunter Mahan 72 67 72 72, J.B. Holmes 72 69 69 73, Martin Laird (Sco) 71 70 74 68, Chris Couch 68 73 74 68, Tom Gillis 67 71 72 73

284 Michael Bradley 71 69 71 73, Bill Lunde 72 68 75 69, Boo Weekley 67 73 73 71, Stephen Ames (Can) 74 68 69 73

285 Brendon De Jonge 70 70 70 75, Charlie Wi (Kor) 71 66 73 75, Bill Haas 70 71 73 71, Brett Quigley 73 68 73 71, Michael Putnam 71 68 71 75

286 Mathew Goggin (Aus) 72 70 72 72, Tim Herron 71 70 73 72, Ben Curtis 73 69 73 71, Jonathan Byrd 73 69 73 71, Derek Lamely 70 69 75 72, Chez Reavie 72 70 69 75

287 Chris Tidland 65 71 75 76, Luke Donald (Eng) 70 72 72 73, James Driscoll 71 71 73 72, Rocco Mediate 69 71 74 73, Tom Pernice Jnr. 66 71 74 76, Rich Barcelo 72 69 72 74

288 Ted Purdy 69 71 75 73, Steve Lowery 67 75 72 74, Matthew Jones (Aus) 70 71 73 74, Jeff Klauk 70 70 78 70, Steve Marino 72 70 69 77, George McNeill 69 67 76 76, Shane Bertsch 69 72 70 77, Josh Teater 67 74 73 74, Nicholas Thompson 68 73 77 70

289 Harrison Frazar 70 72 73 74, Michael Connell 69 71 71 78, Blake Adams 69 72 77 71, Tommy Armour III 74 68 74 73, Andrew McLardy (Rsa) 71 70 73 75

290 Richard S Johnson (Swe) 71 70 75 74, Chad Collins 72 70 71 77, Johnson Wagner 72 69 74 75

293 Jason Dufner 69 71 76 77, Andres Romero (Arg) 69 71 76 77, Craig Bowden 72 70 79 72, Lee Janzen 74 67 78 74

294 Martin Flores 74 68 74 78, Rich Beem 68 74 77 75

295 Michael Letzig 71 71 77 76

298 Blake Trimble 68 74 80 76