Woods builds lead to four shots

THOUSAND OAKS, Calif., -- Tiger Woods, returning to the form that has won him 14 major championships, built a four-shot lead Friday after two rounds of the Chevron World Challenge.
Woods shot a 6-under 66 at the Sherwood Country Club in Thousand Oaks, Calif., for a 36-hole total of 13-under 131. He is trying to win the event, which he hosts, for the fifth time.
A victory here would be his first in 2010, although it would not count as an official PGA Tour triumph. He has not won since his personal life collapsed following his admission of marital infidelities and his subsequent divorce.
His last major title came at the 2008 U.S. Open, after which he underwent season-ending knee surgery.
A victory this week, accompanied by a finish of fifth place or lower by current world No. 1 Lee Westwood at the Nedbank Challenge in South Africa, would again put Woods back on top of the rankings. Westwood, however, took a three-shot lead in that event Friday.
U.S. Open champion Graeme McDowell was in second place by himself after shooting a 69 for a two-day total of 135.
Luke Donald and Rory McIlroy shared third place in the 18-player field at 136. Paul Casey made an ace at the 12th hole en route to a 65 that left him alone in fifth at 138.