American John Rollins overhauled overnight leader Camilo Villegas to charge five shots clear midway through Saturday's third round at the Buick Invitational.A stroke off the pace at the start of another wet and blustery day at Torrey Pines, Rollins rattled up three birdies to reach the turn in three-under 33.

That left him at 13 under overall with playing partner Villegas of Colombia alone in second place after a shaky outward nine of three over.

Americans Nick Watney, after 10 holes, and long-haired Charley Hoffman, after nine, were a further shot back at seven under.

In pursuit of a third PGA Tour title, Rollins made his first move at the par-four second where he rolled in a 12-foot birdie putt to join Villegas at 11 under.

Despite finding a fairway bunker off the tee at the par-four fourth, he struck a superb approach to nine feet to set up his second birdie of the day.

With Villegas starting out with six consecutive pars, Rollins forged two ahead at the par-five sixth after reaching the green in two and two-putting.

The Colombian then dropped a further stroke behind with a bogey at the par-four seventh, missing the fairway to the right off the tee and pulling his approach left of the green.

Villegas fared even worse at the par-five ninth where he ran up an ugly double-bogey.

After finding the right rough off the tee, he punched out a low second and ended up in a greenside bunker with his third. His fourth shot sailed over the back of the green from where he failed to get up and down for bogey.

Rollins, whose third shot there had ended up just eight feet from the flag, narrowly missed his birdie attempt.

Triple champion Phil Mickelson was 13 shots off the pace after 14 holes with Irish world number three Pádraig Harrington a further four strokes adrift after 16.