R3 LEADERBOARD US unless stated -12 Ben Curtis, Jim Furyk -9 Tim Herron -7 Tiger Woods, Shaun Micheel -6 Vijay Singh, Pat Perez, Brett Quigley, Chris Couch Selected others: +2 Luke Donald (Eng)

Curtis carded 66, while 2003 US Open winner Furyk shot 67 to lead fellow American Tim Herron by three shots.

World number one Tiger Woods and former USPGA champion Shaun Micheel were two shots further back with Vijay Singh in a quartet one adrift.

Overnight leader Chris Couch slipped back to join Singh with a 74.

I'm just focusing on the golf swing a little bit and it gets my mind off how I'm doing Ben Curtis

Curtis, who won the Open in the same year Furyk won his maiden major and Micheel triumphed at Oak Hill, birdied the first and picked up further shots at the seventh, 11th and 14th.

The 28-year-old, who has missed 12 of his last 14 cuts, led with Furyk after both carded 64s in round one before falling back on Friday.

"I'm just focusing on the golf swing a little bit and it gets my mind off how I'm doing," Curtis said. "You try not to think ahead of yourself.

"I tried not to get myself in too much trouble. I just went back to the basics, hit the green and the fairways and see what happens from there."

This year has been kind of streaky, good and bad, nothing in between Tiger Woods

Woods moved into contention at seven under with a 67, while world number two Singh fired the day's low round of 65 to reach six under.

"If I would have gotten somewhere near 10 under it would have been great, but I didn't quite get there," Woods said.

"I got it to seven, which is fine. Overall, I guess I've got a shot."

Woods birdied three holes in a row starting at the sixth, dropped his only shot at the 14th, then closed the gap further with an eagle on 15.

"I've been putting well the last two days, which I haven't done all year," he said.

"Normally I'm pretty decent, pretty good, day in and day out. This year has been kind of streaky, good and bad, nothing in between.

"I logged in the time and I'm starting to see some results.

"Hopefully the guys don't run away. If I can put three, four more birdies up there, I should be all right.

"The golf course is not set up all that hard. You'll see some low scores tomorrow. Hopefully I can post one of them."