Mickelson crashes out, English leads

Having seen Tiger Woods forced out after just eleven holes on Thursday due to a back injury, Torrey Pines accounted for another veteran on Friday, with Mickelson's 36-hole total of 146 not enough to see him play on Saturday.

It is Harris English who holds the tournament lead heading into the weekend, with the American's total of ten-under enough to push him two shots clear of compatriot Nick Watney, Jhonattan Vegas of Colombia and Scotland's Martin Laird.

First round leader Nicholas Thompson shot a 73 to sit three shots back, on clear of a group of ten players that includes Ian Poulter, Jimmy Walker and Jason Day.