Tiger leads by four at Buick

Tiger Woods shot a seven-under-par 65 to open up a four-shot lead after the second round of the Buick Invitational.

The three-time defending champion is at 12-under 132 after 36 holes in the USD5.2 million (£2.6 million) event and leads Kevin Streelman by four shots and Stewart Cink by five shots.

Aaron Baddeley, Boo Weekley and Brad Adamonis are six shots back at 138.

After posting a 67 in the first round at the South Course, Woods fired seven birdies at the North Course, which is considered the easier of the two courses at Torrey Pines.

Starting on the back nine, Woods began slowly with pars on his first three holes before making birdies on the 13th and the 16th.

A birdie on his ninth hole moved Woods into a share of the lead with Streelman, and he followed it with three consecutive birdies from the first to third to build a three-shot lead.

A closing birdie on the final hole gave Woods a four-stroke margin heading into the weekend.

Streelman, an alternate who didn't know he was in the event until just before the first round started, held the lead early, getting to eight-under after making birdie on three of his first four holes on the South Course.

Streelman carded a 69 that included four birdies and one bogey.