Woods took advantage of the shortened par-4 14th and a poor finish by Ross Fisher, needing only two holes Friday to turn a tie into a three-stroke lead. Woods, looking to win his first major of the year, is at 6 under through 14.
Fisher and Padraig Harrington, Woods' playing partner and the defending champion, are at 3 under with U.S. Open winner Lucas Glover (70), Brendan Jones (70) and Vijay Singh (72).
Phil Mickelson, meanwhile, is in danger of missing the cut at the PGA for the first time since 1995 after a second straight 2-over 74. The cut was projected to be 2 over when Lefty finished, but was at 4 late in the afternoon.
"I don't know if it will make it or not. I'm not going to beat many people putting the way I am," said Mickelson, who has played sparingly this summer to be with his wife, Amy, and his mother, both of whom have breast cancer. "I've got to get this thing turned around."
Things didn't come nearly as easy for Woods on Friday as they did Thursday, when he shot a bogey-free 67. The conditions didn't help. The air was hot and muggy, the wind was blowing so hard it rattled the flagstick in the cup on the first hole and the greens were bumpy in the afternoon sun. Indeed, the rounds of the day came in the morning, when Tim Clark and Ernie Els each shot 4-under 68. Club pro Grant Sturgeon gets a nod, too, for a 1-under par.
"It is usually the other way around, but this afternoon I think watching is more enjoyable than playing," Geoff Ogilvy said on Twitter.
But Woods showed in that two-hole swing why he's the world's No. 1 and everyone else is just trying to catch him.