Buick Invitational:PGA Tour rookie Brandt Snedeker proved he was not a one-day wonder with a two-under par 70 on the second day of the Buick Invitational to take a three-stroke lead over fellow American Charles Howell.

Following his record-equalling first round 11-under par 61 on the North course at Torrey Pines, Snedeker switched to the far tougher South and added two birdies through six holes.

Snedeker made a 40-foot birdie putt on the third hole before two putting from 15 feet on the par five sixth hole to end his front nine with a one-under par 35.

The 26-year-old birdied the 12th hole to take him to 13-under but quickly conceded a bogey on the 14th before a birdie on the 15th and pars on his remaining holes took the American home.

Bill Haas, Rich Beem and Charlie Wi are all tied for third, four strokes behind.

Defending champion Tiger Woods, seeking a seventh successive victory on the circuit, has seven strokes to make up over the weekend after settling for a level par 72 on the South course.

Woods began the day tied for 14th and moved up to places despite rescuing a par on the final hole with an eight-foot putt after finding two bunkers on his approach to the green.

Phil Mickelson and Vijay Singh both returned 66 on the North, but are nine and 10 shots behind the leader, while Jose Maria Olazabal, joint fifth after an opening 65, crashed out with a 79 to miss the three-under-par cut.

Ian Poulter leads the European challenge, but a 68 round on the North left him alongside Mickelson.

Justin Rose fell back to three under with a late double bogey and bogey while Brian Davis and Greg Owen both missed the cut.