(CNN) -- Tiger Woods dropped further off the pace on the second day of the U.S. Open as Northern Ireland's Graeme McDowell claimed the clubhouse lead with a 68 on Friday morning, placing him in the lead at 3 under at the midway point at Pebble Beach, PGA.com reported.
World number one Tiger Woods (72) scored 4 under 146, PGA.com reported.
World number two Phil Mickelson (66), Ernie Els (68), Dustin Johnson (70) and Ryo Ishikawa (71) all scored 1 under 141, PGA.com reported.
