Jim Furyk made late birdie putts while Tiger Woods struggled on the back nine, giving Furyk a two-stroke lead midway through the World Golf Championships Invitational in Akron, Ohio.
Furyk fired a four-under-par 66 Friday with birdies on the 14th and 16th holes to overtake Woods, who made bogey on the 13th, and double bogey on the 16th while scrambling to a 67. The twice defending champion of the exclusive event is tied for second with Phil Mickelson at seven-under (133) for two rounds.
Heading into round three Saturday, the three Americans are trailed by Stuart Appleby of Australia, Padraig Harrington of Ireland and Darren Clarke of Britain, all tied for third at six-under.
Meanwhile, John Cook used an eagle Friday to fire an eight-under-par 64, good for a one-shot lead midway through professional golf's Reno-Tahoe Open in Nevada.
Cook is 11-under (133) heading into round three Saturday, just ahead of fellow Americans Charles Howell, David Bergania and Jerry Kelly.
At the Canadian Senior Open at Mississaugua, Ontario in Canada, Jim Thorpe followed his course-record 63 with a two-under-par 69 Friday to hold down a two-shot lead midway through the tournament.
Thorpe is at 10-under (132) heading into round three Saturday, followed by fellow-American Walter Hall, alone in second place.
In women's golf, American golfer Moira Dunn has placed herself in position for her first win since joining the Ladies Tour in 1995 by building a one-shot lead midway through the Betsy King Classic in Kutztown, Pennsylvania.
Dunn shot a six-under-par 66 Friday for a two-round total of 10-under (134), placing her in front of Australian Wendy Doolan.