Holmes was the only player under par at the Oakland Hills Country Club with a two-round score of 1-under 139.
Curtis, the 2003 British Open champion, and Rose each shot 67 and Wi posted a 70 to share second place at 140. David Toms (69), the 2001 PGA winner, and Henrik Stenson (70) were next at 141.
Holmes birdied the 12th, 13th and 14th holes but bogeyed 15 and 17.
"After my third birdie, the next four holes were pretty much into the wind right there and I was just trying to make par on those holes," Holmes said. "Glad I got in with (68). But I felt I left a few out there."
Brandt Snedeker (71), Aaron Baddeley (71), Angel Cabrera (72), Sean O'Hair (73), Ken Duke (73), Sergio Garcia (73) and Jeev Milkha Singh (74) were tied at 2-over 142.
Phil Mickelson, the 2005 PGA champion, was another shot back after carding a 73.
"If they water the greens and change some pins, you can shoot under par," Mickelson said. "I'm within four going into the weekend. There's a lot of golf left out here."