Fiji's Vijay Singh carded a six-under 66 to take a one-shot lead over Tiger Woods midway through the Williams World Challenge at Sherwood Country Club, Thousand Oaks.
Singh started the day tied for third with Woods and Scott Verplank, two shots behind first round co-leaders Mark O'Meara and Fred Couples.
Woods followed an opening round 68 with a five-under 67 and is two strokes ahead of Germany's Bernhard Langer, who posted a 68 and is at seven-under 137.
Couples is tied for fourth at 138 with Sweden's Jesper Parnevik after settling for an even-par 72.
O'Meara posted a one-under 71 and slipped to a tie for seventh, six shots behind Singh.
Parnevik fired a seven-under 65 - the lowest round of the tournament - and climbed from a tie for 14th.
Ireland’s Padraig Harrington lies nine shots off the lead after a disappointing second round of 74.
PA